how much change are they doing to the thing? it took me long enough to get used to firefox 2.
There's not a whole lot of change, as in completely moving things around, but what I've noticed, the graphics for navigation have changed and look kinda kewler. There's some sort of tagging feature I haven't looked into. There's a new "smart" bookmark thing that shows your top 10 frequently visited sites. The address bar is more functional, where it shows the page title as well as the URL, and searches based on more specific guidelines than before. Obviously I have studied the change log EXTENSIVELY. Otherwise, it's way faster; pages load faster, clicking to new tabs is faster, and basic navigation is a lot nicer. The other interface graphics are smoother as well.
OH also, you can search for and navigate a very basic form of the add-ons website in the add-ons window, which now also houses a Plug-ins tab. Downloads window has a search feature...
OH AGAIN, the page zooming feature is more sensible now. It zooms the entire page, including images and styles, basically as if you were zooming in on a screenshot, but better quality. The bookmark manager has also been renovated, and appears to be much easier to use.
Basically, it's gotten a few of the same features that Opera has, and more
These are just the things I've noticed during casual browsing, so there's probably a lot more, less obvious shtuff.