gContactSync 0.2 works on all modern versions of Thunderbird ranging from 2.0.0.8 to 3.0b3pre and 3.1a1pre despite several changes (improvements) in the interfaces that let it interact with the address book. This flexibility comes at a cost, however. The constant version checks probably have a slight impact on performance and a definite increase in code size and complexity. I also have to test it in 4 applications on two operating systems: Thunderbird 2, Thunderbird 3, Thunderbird 3.1, and Seamonkey 2.
I guarantee that 0.3 won't be ready for over a month since there will be significant changes. By then Thunderbird 3 should be even more stable and feature-packed than it is now.
So my question to all of you is, when are you planning on switching to Thunderbird 3 if you haven't already? If 0.3 is released in August with support for just Thunderbird 3 will you continue to use 0.2?
I will eventually drop support for TB 2 but I could wait until gContactSync 0.4 instead.
Please let me know either way.