Firefox remains the best browser on the whole, with great features, impressive improvements all-round, a revised bookmarking system and thousands of add-ons to make it easy to perfectly customise.
The improvements in performance are stellar, it's got some well-integrated features than everyone will use (resumable download manager, tag-ready bookmarking) and it offers, overall, a better, richer Web experience. We're behind Firefox and we hope that when the final release is out it'll be just that little bit better to boot.