I'm on some little project for WP7 too. I think that more developers will adopt WP7 when they see it has a clear future. At the moment it's a bit cloudy, we still don't know if it will continue growing or not.

Anyways, being the first on WP7 is risky but can be very profitable. Kik Messenger grew a lot thanks to their WP7 app (the article is in TC, can't search for it now). There are few apps so there is less competition and you can get a lot of new users.