This isn't quite the beta version...

"A false Firefox 3 report on Digg has caused headaches for Mozilla and confusion for users.

The trouble started early on Wednesday morning when a Digg posting claimed that the first beta version of Firefox 3.0.1 had been posted by developers.

Mozilla explained that there was no beta of Firefox available to the public, and that the Digg poster had instead linked to a release candidate for a future beta version."

Quoted from Digg triggers false start on Firefox 3 - vnunet.com

"Users were told that they were welcome to download and test the release candidate, but were warned that it should not be considered a beta release.

Mozilla hopes to have the first official beta releases of Firefox 3 available to the public at the end of next week."

Hope this helps clarify things :-)