Well I'm not reading Carnage, Jeff is, I think, so I can't speak on him. I know he, and a bunch of other villains (and Creed the no ex-villain) took some responsibility for the New York thing ... heck I don't remember much else.
Sabertooth I know is still the same.
Iron Man ... again, not sure but it could have been the SW that reverted him back to ... not as much an ass ...
... but that may be the reason they allowed the move to begin with, knowing that SW was going to change the Universe. Or not.
Havok hasn't been seen, but Marvel just said he is coming back. I am not sure he will be the same as we left him in Axis (inverted into a bad guy), but maybe.
Cyclops ... well, you have to go back to Secret Wars to find out about him.
(though ... well ... never mind. It's comics.)
Red Skull has appeared, but not enough to know what is going on with him, really. And again, I think Remender had plans for the character and that changed when he left Marvel.
Not sure ... I can't remember ... what happened to Magneto in Axis that is now or maybe different?