It depends a) on how much you fly AA, and b) whether you connect.
If your answer to "a" is "a lot," and "b" is "most of the time," then what have you been doing waiting until now to get a membership?
Seriously, though, it's worth it no matter what--especially now that we're all arriving for flights early. Personally, I'll keep my AC memebrship as long as the DFW Terminal A and ORD clubs--the ones with smoking lounges--stay open!