For over a week now, we at INdT are having a GStreamer training course. Edward Hervey (bilboed, or bilbode for brazilians :P) from fluendo is the guy managing the course. He is hosted in my house and we had some fun this week, lots of beers, hacking, you know :). I will post some pictures here soon. So far, i've learned a lot of interesting stuff and also was able to do some hacking, such as the port of rfbsrc to gstreamer 0.10 and the seek support implementation on neonhttpsrc. In the past i had written some patches and plugins to gstreamer, besides some applications centric development, but nothing big, and now i hope i can help more :-).
If you haven't tried gstreamer yet, you should do it now.