Found 4 of my must-haves Chromedit + Titlebar Tweaks Statusbar Clock Spellbound 2 plus a few more here already upgraded to FF2.0 by their author; less risk than me bumping the maxversion...
I found for about 3 days I was regularly getting updates to my extensions. But for some reason when I leave FF RC2 I get the mozilla bug agent coming up. Bloody odd.
I do the custom install and always uncheck that, just in case it's bloaty. And one thing less to go wrong. Finally got the default spellchecker working, I think the previous Spellbound Developer one may have been messing things up. Color/colour says I have a Brit dictionary. Tab Mix Plus (Dev Build) seems to work OK, still a big improvement on the built-in "improvements". edit: There is a teething problem with TMP(DB), the TMP 'Session Restore' acts in addition to the new FF2 one, so close 10 tabs and 20 re-open next time. Fix is to use one or the other, but not both. Turn FF one off by creating a new boolean in about:config, 'browser.sessionstore.enabled' making it 'False'. Or just turn the TMP one off through the TMP Options.
Get the extension 'Nightly Tester Tools' Here http://users.blueprintit.co.uk/~dave/web/firefox/nightly It allows you to enable plugins for older versions. Ive used it to run several old extensions and never had a problem
I keep it on because its beta software, the more info they can get the better it'll be for us in the long run. Tab Mix Plus sounds like its being incorporated into FF2, so it may become just bloat
Only a small fraction of its many features, so I'm prepared to put up with the bloat. Bill's Big List of Firefox® 2.0 Compatible Extensions.