There’s a beta that runs in 64-bit, but the URLs are not Mozilla, so I suspect they are simply home-brewed versions, but if you use them it seems that most of your plugins then fail.
So, Firefox remains 32-bit until 4.0 I suspect. Speaking of plugins, it’s possible to make it look more at home in Win7 using some of the plugins shown on this page. I’ve added:
and the rest I use diffent ones to suit my own needs:
I’m interested in what others use, feel free to post comments…:)