I just saw on the GameStop website (yeah, that GameStop) they have TIE Interceptor and A-Wing expansions listed as preorders for a 7/24/13 ship date, retail price. They don't say how many they're getting, but they say they won't charge you until the order is shipped, so not much risk in preordering I guess.
Seeing how wave 2 is pretty much gone everywhere else now, I thought this might be noteworthy.