Went to the across town WM (the only one that carries the 6" exclusives), and found 3 of the six. They had the "easier" to find ones of Thor, Iron Man, and Cap. I'd like to complete the set, but I'm not sure how often these will get restocked - it didn't seem like the Cap/Thor ones last year got stocked more than once or twice. Might have to try ebay, although the prices are a bit steep.
The 3 3/4" figures seem to be selling decent here now, post-movie. It seems like the pegs are mostly packed with Iron Man, and occasionally Thor, but I don't think I've seen anyone else at the stores I visited over the weekend.