The first release candidate of Firefox 3.5 is out; though you'll need to get it by auto-updating 3.5 beta 4. It's ugly as sin, breaks the back button, breaks the scrollbars, and still hasn't fixed this AppleScript bug. To add insult to injury the feedback page uses a pointless, illegible CAPTCHA:
I think I'm giving up on Firefox. I just need to get del.icio.us integrated into Safari and I'll be done.
They've also released Firefox 3.0.11 to fix a security vulnerability.