it feels just like yesterday that Firefox 5 came out, but it was actually 2 month ago. Now Firefox 6 is already available. The official release is Tuesday, but the downloads have been already spotted at the FTP servers for Linux, Mac and Windows by PCMag and others.
I am actually holding off installing Firefox 6 as my workflow depends highly on two Firefox add-ons and they sure will be incompatible again. I hope the updates will be available soon after the official release of Firefox 6 tomorrow.
The new Firefox 6 is supposed to bring a series of performance improvements. There is no big new feature in Firefox 6.