If you been wanting to try out Thunderbird 2 but been waiting for all the major bugs to be squashed, that time has come. TBird 2.0 Release Candidate (RC) 1 was released yesterday. This is very close to the final product, there may be a few small lingering bugs but nothing major. You can download TBird 2.0 RC1 from Windows, Mac OS X and Linux from Mozilla (note if you are on the ‘Beta’ Update Channel you will be/have been prompted to upgrade).
News Source: mozillaZine