Seeing as how I was almost spot-on in predicting the pegwarmers for TAC wave 1 (I picked Artoo and Obi-Wan), I thought it might be fun to try to predict which figures from each wave will pegwarm the worst.
Wave 2: I'm thinking that Han is the only real candidate for pegwarming here. There's a possibility of Luke and the Rebel Guard showing a warming trend though. Ceremony Luke didn't exactly fly off the shelves in the POTF2 days and the Rebel Guard is just not that exciting of a figure, especially for kids.
Wave 3: Darth Vader of course, I think the demand for this guy has been filled and overfilled, then overfilled again just to be on the safe side. I'm also going to go with Luke again, I don't think there are that many diorama builders to compensate for what looks like a really poor figure.
Wave 4: Easy, Umpass Stay, C-3PO and Luke. Barada from the Saga2 line didn't just warm the pegs, he darn near boiled them. If the only gimmick for Threepio is some green "slime" paint, then I don't believe that will be enough for him to fly off the pegs (especially since the Endor Throne Threepio was something of a slow seller down here). Based on the prototypes, Luke doesn't look so good, so I think that will hurt his appeal.
Wave 5: I'm not sure about this one, if they are widely released like SOTE, then ALL of them, except for Concept Luke (seeing as how the C4 fiasco is going to artificially inflate demand). If they are more like the 1998 EU line, then I don't expect to see a single one on the pegs.
VTAC: Bossk of course, but that's good news for me. Hoth Han, almost for sure (based on the performance of the previous vintage-style Han figures). Maybe Leia, since none of the other Endor Rebel figures have really lept off the shelves either. Actually, now that I think about it, I've never really had trouble finding any of these vintage-style figures. I guess the $10 price tag is a big deterrent for kids.
There's too much speculation in the following waves for me to make any guesses right now. This is also assuming that none of my picks are short-packed.