Thunderbird 2 has recently been released as announced on www.mozilla.org on April 18th, 2007. I have just downloaded and installed it. At first glance, the surface makes no difference to me - except for the fact that my custom theme - CrossOver 2.3 - does no longer work as can be seen on this screenshot, although it is announced to be compatible with TB2. So, I am using the default theme now which is included in the installation package.

At least, I have found a way how to change the alternating colors (the so-called “Zebra Striping”) in the message view as well as the folder view - see the MozillaZine Knowledge Base.

It seems that I’ll have to figure out the new features of TB2 one by one.