Normally when I am staging an upgrade, I will use the latest release -- even if it's only in beta. I spent time off and on testing Firefox 3.1/3.5 and was never able to get it stable enough to deploy. It was crashing way too much, and the core problem seemed to be the interaction with the Flash 10 plugin. I know, I know....3.1/3.5 is still a beta release. But one hates to move out a version into production that is nearly obsolete.
Anyway, I have installed 3.0.10 and all of the plugins including Flash are extremely stable and working well. I'm getting fairly decent frame rates to the thin clients, and the pulse audio streams are working well. I also had good luck with the FoxTab 3D plugin and that too will be pushed live as part of the upgrade too.
I also have been spending time on Evolution 2.24/SLED 11. We have about 30 fulltime users on it, and it's slowly inching to the finish line. We have one more major feature to include (resend of a meeting from the Sent folder). Then comes bug hunting, crash reductions and then some valgrind/leak hunting.