Thunderbird 2RC1 is out!
Although a beta release, with its rich feature set, I was compelled to use it. A complete description of its features is here. With tagging and improved searching, its bound to be liked by many. Also, it is easily integrable with gmail, making it the preferred desktop application! The release is still a beta, and may have some bugs. But, for those who were longing to switching from outlook or try a new interface of thunderbird, this is good enough.