CES 2010 is just getting under way and already everyone is talking about tablets. Lenovo has already unveiled the intriguing IdeaPad U1, a hybrid tablet/laptop that features an ARM-based tablet that can dock into a CULV-based ultraportable notebook. Put the two together and it's a laptop, or pull off the "monitor" and it's an ARM-based tablet.

Then there's the big rumor that Steve Ballmer will unveil a fancy new tablet, built in conjunction with HP, at tonight's keynote address. This Microsoft Tablet is expected to be something different than the typical "tablet PC" designs we have seen over the years (basically small notebooks with reversible touchscreen displays). Everyone is wondering if it will be the Courier tablet whose concept was first revealed by Gizmodo back in September. If so, it will be a marked shift in tablet computing from the Redmond giant.

Of course, no discussion of tablets would be complete without discussion Apple's always-rumored, never-confirmed device. Apple doesn't really participate in CES, and an event is scheduled for later this month that everyone assumes will be about this magical new device. Would Apple dare cannibalize low-end Macbook sales with a highly capable tablet computer? I think they would - if it works like the iPhone and all the apps come through Apple's App Store, the company would be positively dying to sell profitable hardware where it also takes 30% of the sale price of every app.

Why the sudden surge in tablet computers? Part of it could be market forces. The explosion of netbooks shows that consumers seem to want ever-smaller computers as companion devices. They don't need to run all their usual apps, just get online to check email, update Facebook, take notes, and do a little web surfing. The other part could be the technology. New energy-sipping Atom processors together with bigger and more powerful ARM-based platforms finally give device makers the ability to make 7-8", super-thin devices that can actually run full-featured web browsers, and the proliferation of multi-touch screens and software makes these things easy enough to use without a keyboard (in theory).

Quite a few other tablets are expected to be announced during the next few days of CES. Stay tuned to PC World for complete coverage.

For more up-to-the-minute blogs, stories, photos, and video from the nation's largest consumer electronics show, check out PC World's complete coverage of CES 2010.