The third and final release candidate for Firefox 2.0 should be coming out around October 15th. The code freeze is set for tonight at 11:59 PM PDT. There are still several bugs which are being worked out for this RC. There will not be any more theme changes as the Firefox 2.0 theme is done now.
From The Official Win32 20061010 [Branch] Build Page…
Mike Schroepfer wrote: Firefox 2 RC3
There are a handful of security and stability bugs we’d like to see get in before the final FF2 release. Thus we’ll be doing a third release candidate. As with RC2 all check-ins must have a r=1.8.1+ and a comment from a branch driver of “approved for RC3.” Planned code freeze for RC3 is this Tuesday Oct 10 at 11:59PM PDT. I’ll post here if anything changes.
The Firefox Extension Guru's Blog 
[…] With the code freeze for Firefox 2.0 RC3 now in effect, I did some checking on the Mozilla Developer’s Calendar and noticed an estimated ’ship’ date for RC3, Tuesday, October 17th. Also on this same date is this interesting item: Fx2 – Launch Dependencies Due! […]