They do develop really slowly, and IIRC, he pretty much sucks with them the next book, so he doesn't exactly become superpowerful overnight or anything, but when the whole gimmick is that your lead is the only person without powers in a world where everyone has them...

Exactly. It's especially annoying when in that very book you find out that their ancestors DIDN'T have them originally, which... makes it so much more believable and interesting that he doesn't.