Firefox 5 beta 5 is scheduled to release on 7th of this month with Direct 2D turned on. This beta contains new features such as Add-ons manager, two-tiered menu.Firefox 3.6.9 is also scheduled to release on 7th of this month.
Mozilla released Firefox 4 beta 4 with Panorama, Firefox Sync features and Direct 2D disabled by default as they are not confident which might cause systems to crash.
Now in Firefox 5 beta 5 releases with Direct2D turned on.
We already covered about Add-ons manager screenshots and its features .
Firefox 4 Beta 5 to be released with two-tiered menu looks similar to Windows vista menu.This beta also have OOPP (Out-of Process Plugins ) which allows uninterrupted browsing even though plugins crash.Lot of under hood developments and improvements to Panorama and other features.
You can try latest Firefox 4 beta 5 build from here.