The fact is: Starting from the first launch of Bamboo 3.0, we have already officially ceased the support for IE6.
However, you can still install and run Bamboo 3.0 quiet well on Windows machines with IE6. But starting from the upcoming release of Bamboo 3.0.2, Bamboo will technically become incompatible to IE6.
Why does Bamboo require IE? Some of Bamboo's user interface is rendered using Internet Explorer's rendering engine. As of 2010, we found it a big burden for us to keep an Windows XP machine with only IE6 installed and have it tested for every software releases we made, and "double coding" our program to make it IE6-compatible. Hence the decision of dropping it. Hopefully, bringing more value to our users than trouble.
Anyway, for your interest, some people held a funeral for IE6.