Firefox 4.0 beta for Linux, Windows and Mac has hit the servers and, besides the instability warnings, you get 64 bit support on Macs. Grab it from Mozilla’s nightly builds portal. This is a very (repeat VERY) early beta so use caution until it becomes a public beta or the real deal.
Be sure to grab one of these with “.dmg” at the end, and yes… the application file is called “Minefield.”:
The UI is also a little bit cleaner. The PC version has Chrome-like tabs above the URL. Not the Mac. Yet.
Minefield 4.0B blew away Firefox 3.6