In theory, it's possible. In practice, while Google didn't quite go in with malicious intentions to make it impossible, they didn't exactly bother to do the little things that would have made it fairly straightforward either. The kernel interfaces are the same (duh), but the libc (which most folks will be concerned with) is reportedly some sort of twisted mutant (a BSD libc hastily ported to the Linux kernel) that will sometimes be familiar and comfortable until it abruptly backstabs you as soon as you get complacent.

I can only assume cyanogen and similar mods either have one heck of a fun time handling that... or they bit the bullet and ported (e)glibc over or something.

Frankly, though, I don't think that addresses the real issue with Android as a migration target. For example - I managed to turn my n900 into a bluetooth network hotspot (see here: http://talk.maemo.org/showthread.php...84#post1327284). I have real doubts that something similar could be done with Android without running a bunch of extra "helper" glue code bits that run on Dalvik. By contrast, putting together that was easy - all I had to do was familiarize myself with how to do it on a real GNU/Linux desktop (about an hour's worth of reading) and then adapt it to the phone (about another hour).