Google is great at bringing carefully planned, methodically disruptive technology into our lives, but I think they would fair better if they surprised us with a web OS, rather than a desktop based, open source solution. A direct threat to Microsoft's core product is not a conceivable victory (but then Google advertisers would be happy). However, if Google were to go full court on something like a web based OS, it just may raise some interest, and create a stir. I think I may bet on this one, since the odds are high. This is definitely something to watch for.