Google's mobile masterplan

I think there is an ongoing pattern in Google - they are just keep fitting in to all existing niches, taking only the best elements from each competitor or firm in the niche and adding to the mixture their secret sauce, which will finally make their product the best. Notice that they're conquering (and not slowly..) every niche in the market and I'm sure we haven't seen the latest... Pure Google-Made OS is the destination, and it will be substantially better although it was built upon OSX/Microsoft/Linux elements.. That's how you gain popularity.. upon popular "ancestors".

Google using Linux as a base OS to deliver Chrome+Applications?

I'm not holding my breath. One only has to look at how they handled Chrome to see how they will handle the OS. Instead of taking an established open source browser like Firefox, Google started from scratch and took the best from FF3, IE7 and Opera to create Chrome (along with their own special sauce)

If we translate that to the OS, they'll take the best parts from XP/Vista, OSX and Linux and create their own. There's simply too much legacy, assumptions and classic thinking in your typical Linux distro for Google to be interested.