where does it say they're using Linux as a base? Im not saying they aren't: it's just there is no suggestion they are. and, y'know the press release feels like a level shot at all modern OS's. Unless they've said otherwise I reckon were looking at something new (which is great IMO)

EDIT: bleh I read from the bottom up (in terms of the front page) so Google Blog was last :) I see the source.