Recently I thought I would try out the Mozilla Firefox 3.6.4 Beta, so far I have been pretty impressed with the release, therefore I doubt that the proper release will be too far away.
The main difference between Firefox 3.6.3 and the 3.6.4 beta is a new feature which is designed to decrease browser crashes, if a plugin such as Adobe Flash, Apple Quicktime or Microsoft Silverlight crashes whilst using Firefox 3.6.3 the web browser would be forced to restart, however the 3.6.4 beta has changed this.
Now instead Firefox will not crash (hopefully), it will instead restart the failing plugin and try again, Mozilla hope that this should help Firefox provide “uninterrupted browsing”.
Obviously there are other less-significant changes as well, there are said to be plenty of stability and security changes along with a long-list of bug fixes, which can be seen here.
If you would like to try out the beta check out this link, however as you probably know the beta features unfinished code, which could perhaps offer a less stable web browsing experience.