Well Firefox 3 over all seems faster, they have included an auto complete on the address bar, which I think is pretty sweet. The GUI was changed slightly but nothing too dramatic.

What really astonished me was the new Opera browser 9.5, wow, that is all I can say wow. This thing has everything and a litttle bit more. Anything you would expect and need from a browser it has. First it has all he features that firefox has, plus cooler widgets. And finally someone gets the clue about bookmark synchronization, wow, the service is amazing and it is called opera link, check it out here:

http://www.opera.com/products/link/