* Will they really put all their weight behind it? My guess is that there's an internal struggle between that and Symbian.
* Will they be able to make it as nice as Android? I care about the fact that it's open source and hackable, but what most people are going to worry about is how well it works, and what the application writing process is like. I doubt there are many Debian apps that are all that useful as-is on a phone - maybe in 5 years, but not right now.