This stuff just keeps getting better and better. Finally the nasty bug with (I presume) totem-xine, nvidia-glx and Xinerama whereby the "Leave fullscreen" and current progress dialogue never disappears has been fixed. This isn't GNOME 2.13.3, per se, just an update to totem, which is a part of GNOME. This is great as it means I don't have to kick in my nasty workaround.
Watching GNOME development is one of the most most amazing things I've seen. I guess it might be like the Linux kernel development but in a way that you can see things change almost in real-time. It's very impressive.