It seems that the folks over at Mozilla are thinking about another release candidate or adding another beta version, prior to the final release. Seems that not is well with version 3 and the team has some concerns that need to be addressed. On there site it is stated:

Hi Folks,

The QA team is still doing directed testing and we are collecting
feedback on RC1.  We’ve been triaging the bugs and so far have 10 bugs
that look of the highest priority:

http://tinyurl.com/3ev27v

We are going to approve these to land on trunk so we can get regression
and nightly testing on them.  If we need to do an RC2 they’ll be ready
to go – if we ship RC1 we can get them in the 3.0.1.  If you are an
owner of one of this bugs your assistance in landing them would be much
appreciated.

ONLY patches with approval1.9+ can land.  We want to keep this to
*critical* bugs only (e.g. common crashes, severe breakage of major
functionality, etc) – if we have to do an RC2 the test/feedback cycle
will be shorter than a dot release.

Best,

Schrep

Hopefully the folks at Mozilla will be able to get the bugs ironed out and the final release will be the best Firefox yet.

Comments welcome.