E.Vi.L. said:
The big difference is that GG's origin is known but Abomination hasn't been introduced.
If more than one of these theories are right (Crimson Dynamo, Red Skull, Abomination...) it is going to turn into a nightmare.
A lot of thing can be said about Millar but he hasn't tried to cram issues with new character. Except at th every beginning and look how slowly he introduced all the team before getting to the action. He can't do the same here because there isn't enough issues left.
I'm thinking we get one significant new character before the end of volume 2, top. Any other new characters that appear is liable to get batted out of the way casually as if he were a red shirt (which he'll be, in a way).