Looking really good - I especially like that Google is creating something a bit different from the iPad here. It's all about widgets, and updates, and streams of data. Well, that plus a hefty dose of Apple copying.
Google looks like it's 18 months behind now - the iPad 2 is around the corner, ready to take the spotlight from Android 3.0, and ready to make it look old again.
Microsoft showed a version of Windows running on ARM, and will push Windows 8 for tablets. Almost irrelevant at this point though as they're probably a year or more behind Android - I don't think they'll be able to catch up in any significant way.