Agree, first impressions are good, as Wige says, its client side scripting that should show a difference if the PR is correct, which will be great if it works out for web based applications. It's based on Web Kit, again as Wige noted, The WebKit Open Source Project (as is their mobile browser and the Safari browser).

I like the Opera style homepage too. I think your right on the money Peter about Microsoft here, and Google seeing this as their first step into an operating system albeit an online one.