We have previously covered a long list of potential iPad™ alternatives. Unfortunately, after we wrote the original article, most of the tablets covered were either cancelled, or delayed until further notice. Of the few that were released, they can best be summed up this way: there is no alternative currently on the market with equal capabilities to the iPad.

This is fine. The iPad truly is a remarkable device and will be certainly hard to beat. But some companies are very focused on trying, and so we wanted to compile a list of some of the most promising devices set to come to market this year. This list is quite extensive, so look for the continuation of this blog later this week.

We recognize that this is not a complete list, and some were covered in a follow up to our original posting. This includes some very promising tablets by HP, Lenovo and others. It is totally worth checking out, but since we already covered them there, they will not be listed here. If you are interested, you can read the iPad Alternatives Redux Part One and iPad Alternatives Redux Part Two.

As for this post, we will cover a bunch of new apps. Unfortunately with the great – and ever increasing—number of tablets, this may be our last coverage of tablet devices. After all, we develop custom software for tablets and slate devices, so we can’t spend all our time drooling over new platforms.

But, if we happened to miss a device that you are really excited about, please let us know!

EEE Tablet by ASUS

Features: Asus has two tablet devices coming out in the near future. In a slightly confusing naming scheme, the ASUS EEE Tablet is essentially a digital notepad and e-reader, whereas the ASUS EEE Pad is a tablet computer.

Even though the EEE Tablet (digital notepad and e-reader) relies on a stylus, it is actually remarkably impressive. In Asus’ own words, "the humble notepad is in line for a digital makeover." In fact, it has a highly-accurate screen with input sensitivity of 2540 dpi, which allows people to make digital notes "like you’re writing on paper," according to ASUS.

Those that have been lucky enough to play with the device noted that the screen refreshes much faster than traditional e-reader LCD screens, and that stylus was very easy to use and responsive.

Full specs have yet to be released, but it will also come with a 2 megapixel camera for capturing lecture slides, Wi-Fi, which allows the download of books and apps, as well as offering a syncing and a USB port and microSD card slot for transferring data.

No word on the operating system for the EEE Tablet, although it seems that this will likely be an "as-is" system in terms of software, with only a limited ability to add third-party apps. But that may be just fine for this type of tablet.

Release Date: The EEE Tablet will cost between $199 and $299 and should debut sometime in September.

EEE Pads by ASUS

Not to be confused with the EEE Tablet, the EEE Pads are actually a full service tablet computers. They come in two models, named the EP121 and the EP101TC.

The EEE Pad EP121 is a smaller version (pocket sized) that is based on a compact version of Windows® 7 called Windows Embedded Compact 7, which focuses on touch input, and interconnectivity between devices, the Web, and PCs.

Some benefits of Windows Embedded is that it natively supports Silverlight®, Explorer®, Media Player®, Office viewer, and many other standard Windows software. Oh, and it supports Flash® 10.1. The downside is that input recognition still seems to be slow and buggy on tablets that have tried running on Windows 7, which could possibly be a hardware issue, or other software issue (such as custom UI’s), but likely is mostly due to an underlying issue in Windows 7.

The larger version, the EEE Pad EP121, boasts a 12 inch screen and runs on Windows® 7 Home Premium, and is powered by a CULV Intel® Core™ 2 Duo Processor. Even with all that processing power, it still claims to have as much as 10 hours of battery life. The larger EP121 also features a keyboard docking station which essentially turns it into a laptop for quick typing.

Kno by Kno, inc

Features: Created by Kno, Inc, the Kno is being pushed as "revolutionizing the textbook," with an obvious push towards uses in education and reading. In fact, it acts much like a textbook with dual panel multi-touch displays that can be folded open like a book, or folded in half to act as an individual tablet for writing and note taking.

The Kno also lets you take digital notes through a stylus or external keyboard, and drag pictures from the web or your e-textbooks into your notes. Users can also take notes over the top of their textbooks, or highlight text and copy it into their notes. In terms of an Internet browser, the Kno offers a full-featured browser that supports HTML5 and Flash 10.1. The Kno also syncs to a server so that users can access their notes and books when their Kno is not accessible.

Another interesting bit about the Kno is that each 14.1" display has its own battery, and so the device has about six to eight hours of battery life. The device also has Wi-Fi and Bluetooth capabilities.

In terms of performance, it has been reported that the Kno will be running on a Nvidia Tegra 2 graphics chip, but will only have 16 GB of internal storage for text books or other media. There is no indication that there will be any expandable storage, such as a removable microSD, but cloud syncing may help alleviate the problem. The device also weighs in at 5.5 pounds, making it one of the heaviest tablets in this list.

This device is based off of a Linux and Webkit operating system, and comes preloaded with many apps, including interactive flash cards, a calculator, calendar, collaboration tools, and email and Internet. E-textbooks can be purchased through many of Kno, Inc.’s textbook partners, and standard e-books will also be available.

For third-party applications the Kno will be very developer-friendly, supporting web technologies such as JavaScript, HTML 5, and CSS. In other words, applications for the Kno will be similar to the development process for Rich Internet Applications. The Kno SDK (software development kit) also offers some unique APIs that call for programming support for the stylus, dual touch screens, and other contextual menus.

Release: No firm release date has been set, but preorders are tentatively scheduled to start around mid-October with devices shipping sometime in December.

Galaxy Tablet by Samsung [Rumored]

Features: Rumors: The Samsung Galaxy Tablet’s existence was initially revealed by an accidental tweet on the company’s official South African twitter account, along with an accidental picture. Does it sound skeptical? Yes, but then again, Apple® revealed the iPhone 4 by leaving it in a bar, so anything is possible.

Samsung currently has a line of Galaxy brand phones, which run on Android 2.1. In a follow-up confirmation, the company confirmed that the tablet will have a 7-inch TFT Display, and will run on Android™ 2.1 with the same TouchWiz 3.0 interface as the Galaxy S. In essence, this is a big version of the Galaxy S, in the same way that the iPad is a big version of the iPhone.

Other reports indicate that Samsung will follow up on the 7-inch model with an 8-inch and a 10-inch version later this year. All versions will come with a front facing camera.

Running on Android 2.1 (or hopefully 2.2 or higher by release time) give it access to the Android market. For Android app developers, this can provide yet another benefit, as it allows them to reach an ever-expanding market, which can have a big impact on the return they see on their development costs and other investments into their apps.

Release: The 7" tablet, possibly called the sPad, may be released in Africa as early as August, with larger versions premiering later this year; however there are no confirmations on those dates, and no word on a US launch.

Skiff by Skiff

Features: Without getting your hopes up, this product is most likely dead. The Skiff platform was sold to News Corp, but not the hardware, leaving the device’s future very unclear but not very hopeful.

We are featuring it here mostly because we still really like the idea of a super thin and lightweight e-reader, especially for print media such as newspapers and magazines. From an industrial design point of view, this is also the only tablet that doesn’t look like either an unplugged computer monitor, or a giant phone. And maybe somewhere deep down, we hope that this will still come out.

Some of the features that we liked, besides the giant 11.5-inch display with 1,600 x 1,200 resolution, which was big enough to fit an entire newspaper on the front page. Also, Sprint had lined up to provide the data network, allowing users to wirelessly access content, such as newspapers, magazines, and e-books.

Either way, Hearst is still on the radar, after developing another prototype Skiff reader that used color electronic ink. In this Skiff prototype, Hearst showed versions of magazines with full color ads, color photos, and video.

Release: Unknown, but likely never in its current form. However, Skiff still exists as a hardware company, and with Color E-Ink capability, they have the potential to produce some really amazing devices.

Cius by Cisco

Features: Cisco’s entry into the tablet market was a surprise at first, but seeing how they have integrated it into their network devices and WebEx products, it actually makes a lot of sense to release a tablet product.

The 1.15 pound Cius (pronounced "See-us") is targeted towards business and education uses, and runs on Google’s Android operating system. In fact, the company chose to go with the Android OS specifically so that users will be able to tap into the Android developer community.

The Cius also features front and rear facing cameras that can record in high definition (720p HD at 30 FPS for the front facing camera, and a 5-megapixel rear facing camera), for video conferencing, and the Cius integrates with Cisco’s TelePresence video conferencing system to provide one-click access to video calls.

In other words, the Cius is primarily a collaboration device. Although it does have very impressive video capabilities, and a respectable 8-hour battery life, it is not being pushed as a consumer-centric device. Instead, the focus is on the ability to connect and collaborate.

It also comes with WiFi, 3G/4G data connectivity, Bluetooth, and support for USB peripherals.

Release: No set date, but consumer trials are set to start early fall, and should be released early 2011.

Que ProReader by Plastic Logic

Features: The biggest differentiator of the Que ProReader is that it is built on internal components embedded in plastic, rather than silicon, and keeps the 11-inch device down to only a pound. Otherwise, it is a fairly standard feeling e-reader, similar to a Kindle™, for example.

Que is branded as a "business reader," which means that in addition to e-books and magazines, it can also display and add notation to business documents, such as Microsoft Office documents, PDF files, and e-Pub documents, for example.

Users can either download these documents from the Web, from emails, or by direct transfer from a PC, Mac®, or Smartphone. Que comes with WiFi and 4GB storage, but can upgrade to 8GB and AT&T 3G as well.

Otherwise, it appears that Que will be a closed program, which limits third-party development options.

Release: Delayed, again. This is the second delay and missed deadline, and the company has not announced a new target date but says it is still continuing the project. It was initially being offered online for $649 - $799 depending on the model, and was scheduled to also be sold in Barnes & Noble stores nationwide this fall.

To be continued…