Just downloaded and installed Firefox 2.0.  Wow, everything seems to be faster!!  Check out what is new, includes tabbed browsing, spell checking, search, web feeds, identity theft protection, proven security model, and customization. I did run into some problems with the upgrade put had a  backup copy of everything using FEBE.  Would recommend that you take a backup before upgrading so you can restore preferences and add-ins if need be.