jimbo007 :
Android as it is, is not suitable for as a desktop OS. The kernel and process scheduler among many other core components are optimized for a OS running on a battery with limited power supply and thermal envelope. Running a desktop OS driven with mouse/KB with true multi-tasking and running on AC power requires substantial changes to the OS core, essentially reverting back to its Linux origins! I don't know at what stage is this "Remix OS".
I don't understand what you mean by optimized for battery devices. Windows works fine both on a desktop and on a laptop with a battery, or even some tablets, so what are you really trying to say? You don't need to change Android's core to make it run on a desktop. You don't even really need to change much to make it work with a keyboard and mouse.
For one, keyboard stuff is already used and two, you just click the mouse where you would have tapped with your fingers. Things like zooming in by spreading fingers on the screen might need to be changed, but there should be less need for zooming anyway with the more full-sized display and that's still easy to implement with minimal changes.
No computer actually runs on AC power. They all have power adapters to convert to proper DV voltages for components such as 12V, 5V, and 3.3V. Furthermore, the OS doesn't care what kind of power is being used. The OS has literally no impact on this.
Android already supports true multitasking.