Novell and OSNews are currently sponsoring a bounty hunt by Ben Maurer for improving the memory usage in Gnome. There are currently 4 bounties set starting with 100USD for improving the icon cache. The overall goal is it to make Gnome more usable on machines with only 128MB RAM. While it would be great to have some of theses fixes already in the 2.10.x releases the target timeframe seems to be the 2.12 release.
For more details please check out Ben Maurers blog entry about this :-)