The improved tabbing feature is kind of a moot point since I don't really make use of tabs....I think I'm the only Firefox user who doesn't really make use of tabs.

But this:

"Session Restore

Losing your place while you’re doing things on the Web is a pain. Now, with Session Restore, if Firefox has to restart or closes when it comes back you’ll pick up exactly where you left off. The windows and tabs you were using, the text you typed into forms, and the in-progress downloads you had running will all be restored. You can even set Firefox 2 to always restore your previous session instead of loading a home page, so you’ll never lose your place again."

That is an awesome feature. Especially when Acrobat TRIES to load and just ends up locking Firefox.

EDIT: how rude of me....Thanks for the link!