Feb 2, 2011 18:01 GMT  ·  By

Firefox 4.0 Beta 12 has become more of a sure thing and less of a plan “B” for Mozilla, which is still struggling to fix all the severe bugs preventing the successor of Firefox 3.6 from being finalized and released. Las week, when I first wrote about Mozilla exploring the possibility of delivering no less than a dozen Beta development milestones of Firefox 4.0, Beta 12 wasn’t a sealed deal.

This is no longer the case, as the open source browser vendor will indeed Build two more Betas of Firefox 4.0.

Beta 12 was confirmed officially by Christian Legnitto, Firefox release manager at Mozilla.

“The current plan is to build [Firefox 4.0 Beta 12] when the remaining betaN hardblockers are done. This is heavily dependent on fix and blocker creation rate.

“I will be doing some analysis to give people a possible date range, but as far as development is concerned everything is the same (fix as many betaN hardblockers as quickly as possible),” Legnitto stated.

Mozilla is currently hard at word wrapping up Firefox 4.0 Beta 11. The company had said that it planned to deliver Beta 11 to early adopters for testing this week, but a specific release deadline wasn’t provided.

The launch of Firefox has already been postponed considerably since it was supposed to be finalized ahead of the end of 2010, and chances are that with yet another Beta on the way after Beta 11, version 4.0 will be delayed even further.

According to Mozilla’s latest plans made public for the release of Firefox 4.0, there was a chance that end users could have received the browser by the end of February 2011.

With Beta 11 and Beta 12 still on the way, and then at least one Release Candidate (RC) following them, Firefox 4.0 could slip into March 2011.

Firefox 4.0 Beta 10 for Windows is available for download here.

Firefox 4.0 Beta 10 for Linux is available for download here.

Firefox 4.0 Beta 10 for Mac is available for download here.