I recently added support for GtkSourceView 2 to MonoDevelop, and it can be enabled with the "--enable-gtksourceview2" configure switch. Unfortunately the Boo Binding and the Database Addin depend on GtkSourceView# directly, and aren't compatible with the API changes in 2.0. I may get round to fixing them later. However, I've already switched on GtkSourceView2 support in my MonoDevelop build repository. The main reason I did this, of course, was the wonderful dark grey colour scheme "oblivion" :-)
