Chrome land: they've got official beta versions of Google's browser to call their own. Of course, people have been running the open source Chromium version on both sides of the fence for ages, but beta brings with it a new level of stability and officialness. Google is also finally launching extensions for Chrome, which is available for the Windows and Linux versions of the browser, and with Mac compatibility on the way. There are already 300 extensions available, not a bad start, and hopefully a good indication of the sorts of added functionality we'll be able to stuff into Chrome OS with the help of a seemingly-excited developer community.
[Thanks to everyone who sent this in]