Already, using Windows 8 feels a lot like running VMware on a Linux box did 10 years ago. Win8 Start is the new Ctrl-Alt-F8. It feels like two systems in one. Adding Android as a 3rd option would be a logical step.
Then I believe there will be virtual Android apps on the PC desktop, virtual iPhone apps on Android phones, and eventually, even virtual Win8 tiles on the Windows desktop :-)
And at that time, everybod will have access to all apps, and nobydy knows which OS is running in the bottom of it all.
Borge