Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.
In the CES keynote Steve Ballmer explained the HP slate tablet are "more powerful than a phone and almost as powerful as a PC. Perfect for reading, surfing the web and taking entertainment on the go," Ballmer showed the HP tablet running Amazon's Kindle software and played a video on it. Microsoft adopted the name slate computer to distinguish it from the pen-and-screen dealy introduced by Bill Gates in 2001. However, its not the real name for the tablet PC. Lets wait for the Slate!!
Update : 07 Apr 2010 - HP Slate info - leaked !!
http://www.engadget.com/2010/04/05/hp-slate-to-cost-549-have-1-6ghz-atom-z530-5-hour-battery/