on the wishlist page, it needs to be ported to gst 1.0. (gstreamer) Fun to see someone else try something adventurous! I think most projects use telepathy with ofono for telephony, so it's probably a sane choice for that. I can't really comment on gabble. The EGL issue you're seeing might be related to how we have packaged PowerVR on the Nokia N900.
As far as Gtk3 goes - indeed. We need a Gtk3 theme, and we need to forward port the hildon widgets. Probably in that order.