Edd has posted another well-written and thought out blog over on planet gnome. I just wanted to second what he said and add some thoughts about documentation.
Some of Gtk is documented very well, but you quickly go down hill if you need explanations in a language other than C, or one of the other libraries. Although we have the advantage of looking through others source, documentation is often much easier for people outside the regular group to find what they need.
I think we need to have a way for the api docs on http://developer.gnome.org/ to have examples in multiple (programming) languages and be filtered for the users language of choice. This of course means we need to include bindings for other languages in the gnome releases as officially supported languages.
Hopefully we can convince some of the GNOME supporting companies to employ more resources to documentation, even if it's just some interns or part-time employees. It can be overwhelming for volunteers (I should know because I wrote/ported a lot of the Gtk# docs).
Last, I wanted to mention that this page has been very helpful in learning some of the things about GNOME/GTK that I didn't find anywhere else. I only wish I would have read it _before_ we began porting SharpDevelop to MonoDevelop.