The reference council member Tarrlok made to a similar situation 42 years ago with a guy named Yukone seems very promising, especially if the flashback of Korra was about that.
Based on the title of the next chapter, The Spirit of Competition, it seems to go about pro-bending
Dunno if I'm looking into this too much, and I realize that it's just a phrase, but with the last chapter I don't think that it would be too far-fetched for the "Spirit" part of the title to refer to Korra having her first spirit world experience. Though it's probably too early for her to actually speak with Aang or another avatar. I mean, pro-bending is cool and all, but I highly doubt that there will be any episode just about the sport.
Anyway, I'm loving Amon's character right now. Calculated, indefinitely skilled, and he's mysterious but has no problem making his presence known. I dunno whether or not this series will be better than Avatar, but I have almost no doubt that Amon will be a much better villain than Ozai. I mean, we only really saw anything from him in the season finale, the Day of Black Sun, and a few bits here and there in Zuko flashbacks.
As for his identity... personally I'm not sure if he lied about his history, in which case he would have to be someone that we never knew before. I mean, I get that spreading propaganda is probably his biggest weapon, but... I dunno. In the case that he did lie there are still doubts. Just because his face is hidden doesn't mean that he's someone we already know. There are logical reasons. He needs to make himself known as leader without ever risking getting caught. My guess is that we'll meet Amon at some point and have no inkling that it's him. He'll act like a completely different person, have an entirely different identity and there won't be the slightest allusion to it being him. No one, not even his most trusted Equalists, will know who he is to assure that there is no risk. And gradually we'll get small hints that he is part of the Equalist movement, leading to him being revealed. It seems like the most plausible thing to me.