I can speak only for myself, but it would be nice to have the community significantly involved around the project. It doesn't bring much market share, but it brings some die-hard fans.
First thing that would be needed for that would be a single place with a forum, a wiki and dev repo/infrastructure (this is sadly missing for the N9).
Feeling welcome is very important, but that's difficult to define, it's made of a lot little things. That was done pretty ok during the Nokia time (at least on the engineers side), so I'm not too worried.