VMWare had shown something - Horizon Mobile I think - that was a stab at virtualizing mobile OS on other OS's. Same for Alien Dalvik which basically added a layer to allow for Android app usage on other mobile OS's.

Blackberry has the Runtime for Android apps, so it's not that folks haven't thought of this - I swear VMWare showed virtualization on an iPaq 2210 back in 2003 - but nobody has done this to a point where we'd call it a success or that it's been highly visible.

Alien Dalvik got close, but they switched to a model whereas they wanted an OEM to buy it. Nobody bought it.