If you want to see this happen, your best bet is to help out with Fernvale, it's pretty close to what you've described (the phone/microcontroller part anyway, could add an additional CPU for desktop use). Here's a blog post about it: http://www.bunniestudios.com/blog/?p=4297

Fernly is the work-in-progress OS for Fernvale: https://github.com/xobs/fernly