All three of these devices should be available some time in 2010, priced under US$500, but such details are yet to be finalised.
Steve Ballmer whipped out the Windows-powered HP Slate at CES, hoping it will be Microsoft's white knight in the slate wars. It runs Windows 7 on a 10-inch display - so you know it will run all the applications you want - plus it will support Flash and multi-tasking. It's also expected to feature a USB port and webcam. In short, the HP Slate promises to be everything the iPad isn't.
While Windows 7 is the HP Slate's strength, it will probably be its weakness as well. Previous Windows-based tablet devices have failed to excite because the interface isn't designed from the ground up for a handheld touchscreen-friendly interface, nor are most of the apps. An iPad killer has to be more than a netbook with the keyboard ripped off.
Notion Ink's Adam
Amazon's Kindle is a great e-book reader thanks to it's E-Ink screen technology, but it's no competition for a true slate computer. Notion Ink's Adam promises the best of both worlds.
The Adam runs Google's smartphone operating system Android on a 10-inch display, so you know it will be touchscreen friendly and you know it will have access to a mobile-friendly apps store. It should also offer the option to boot into Google Chrome OS and Ubuntu.
The Adam's secret weapon is its Pixel Qi transflective display, a capacitive touchscreen which can operate in two different modes - as traditional full color LCD or as a low powered e-book style display that's easy to read in bright sunlight.
Fusion Garage's JooJoo
A dark horse in the slate race is Fusion Garage's JooJoo, which grew out of Michael Arrington's CrunchPad project. The JooJoo features a 12-inch multi-touch capacitive display and runs a custom operating system. It won't let you install apps, it just boots directly into a browser (reportedly in 9 seconds). Garage Fusion has announced plans to launch a "web store" to make it easy to find web applications that will work with the Joojoo's browser.
The device does feature a USB port and a 4GB solid state drive, plus it reportedly has full Flash compatibility and the grunt to run 1080p content - which might make an impressive browing and video playback device.
It's a dust magnet and the screen hates sunlight, but the iPad is undeniably slick. Read our First Look review.
Is the iPad outrageously overpriced? You might also be interested in joining the discussion here.
Also see William Maher's story debunking common criticisms of the iPad.