you're wrong on this tootsie
AWE is a good program, but they're trying to confuse the webmasters each year even more
anyway, just check the sign up page for new webmasters at AWE.
Basicaslly, every one can join, he just needs to join through someones ref code.
Threads from various boards are posted there where people say how great AWE is, and the new webmaster needs to join through someone... but this has nothing to do with being truly "invite only".
I think this is mainly a part of the re-organisation of their webmaster referral program (there have been threads about that already as well).