I have often wondered when Google would begin to develop an alternative to the windows platform - something for the rest of us...
But it is already out there in plain sight - just smuggled under the radar in the form of a "phone operating system".
Take a look at this post from Engadget - there is a video clip of a "smartbook" - an ASUS Eee PC prototype running google's "Android" on a 1GHz Snapdragon chipset. It is incredible, and the power use is so low that they didn't need to include a fan...
Make sure you watch the video clip to get an idea of the performance: