Late Friday, Mozilla issued what is likely the last development cycle update for Firefox 4.
Firefox 4 Release Candidate 2 (RC 2) has the shortest bug list of any release in the entire Firefox 4 development cycle to date.
The big fix is the blacklisting of a number of invalid HTTPS certificates. Sure they may sound minor, but it’s actually a big deal. Invalid certs on the shipping version of Firefox 4 would enable attackers to phish/spoof and do other bad things to users of fully patched versions of Firefox. By fixing this issue now, Firefox 4 will be more secure, right out of the gate.
Beyond the HTTPS fix, RC2 has updated localizations and included one for Vietnamese. In total, Firefox 4 supports 83 localizations.
Pending any kind of late breaking issue (which I highly doubt), Firefox 4 is set to be generally available tomorrow – Tues March 22nd.