In the year since Apple introduced its trend-setting iPad device, the company's would-be challengers have bumbled around like Moe, Larry, and Curly in a "Three Stooges" skit, bouncing off of each other and ultimately releasing little in the way of credible competition. This week, however, a legitimately credible challenger emerges in the form of a tablet-oriented version of Google's Android OS, codenamed Honeycomb. And it looks like Apple is going to have a serious battle on its hands this year, at last.

Google previewed Honeycomb at CES but the official unveiling occurred yesterday at a special press event. And reactions from this event—which you can view on You Tube—have been universally positive.

Honeycomb, or Android 3, Google says, will only ship on tablet devices. Those with Android phones will see various Honeycomb features appear on those devices over time, though it's currently unclear how Google will differentiate the product versions. (Currently Android phones utilize various Android OS 2.x versions.)

And there are many important changes coming in Honeycomb, including support for hardware accelerated 3D graphics and animations, big multitasking UI changes, video chat, and a new, tablet-optimized UI that isn't just a stretched out version of a phone UI, as is the case with the iPad. At Wednesday's press event in San Francisco, Google showed off Honeycomb on the Motorola Xoom tablet—which also debuted at CES—and the performance of the device appeared to be impressive.

In a related announcement, Google also unveiled a web-based version of its Android Marketplace, allowing customers to purchase Android apps from any web browser, including those on PCs. To test the service, I purchased a game from the web and then watched as the download started automatically on my Android device. Notable too is the fact that the web-based version of the marketplace is actually clean-looking and well-designed, in sharp contrast to the phone-based marketplace.

As for Honeycomb, the new Android tablets will face a second generation iPad as well as other competitors such as the HP webOS tablets and RIM's PlayBook. And in some far distant future, Microsoft's partners will ship Windows 8-based tablets with a next generation Windows Phone "tiles" user interface. By that time, of course, tablets could be well on their way to becoming the mainstream computing device for the masses, replacing the traditional PC. These Honeycomb tablets are the second step to that future.