The latest release of WordPress is now available. I've installed it in a sandbox, and I have to admit that I really like the new look of the admin area, courtesy of the folks at Happy Cog (Jeffrey Zeldman, Jason Santa Maria, and Liz Danzico specifically). Thankfully, my theme still works in the new version, as does Spam Karma and Official Comments.
I want to spend a little more time with the sandbox, but I'll probably migrate this site to 2.5 in the next few days.