Bets for a replacement:
Punisher has a poor chance in hell. He took the costume at the end of civil war, but he's a freaking psycho. Not bloody likely.
Hawkeye has decent chances, but doesn't really want the job. He was already asked to give the costume a shot, and did pretty well with it, though he dislikes Iron Man and was told off by some unregistered hero kids for wearing the costume in the first place. Has said no, but is probably the man who was closest to fitting the ideal of captain america, a human man at the peak of human condition but still only human, a close relationship/rivalry with the man, and he has the inspire and get others to do what he says. He's shown his leadership abilities with the Thunderbolts, although that got screwed over when he spent time in jail and they went to another dimension. Still, he's a respected hero, and wasn't involved officially on any side of the civil war conflict, so nobody really has a reason to hate him except for his former reputation as a villain (which he's long been forgiven for) and as a member of the thunderbolts (ditto).
Winter Soldier is the most likely candidate in spite of his history. As Cap's former partner, and how he's heavily involved with the current going ons of Cap's comic book, and the he's willing to arm himself for lethal damage (hence the black look in those pics), he's a pretty good bet.
USAgent...is in Canada. I don't think more needs to be said there.
Someone new...not likely. Less likely than even the punisher.
Peter Parker. Well, his books are in the toilet (not particularly sales wise, but writing wise...). I could see it happen as a stunt to raise more attention to him with six books called "The Amazing Captain America", "The Sensational Captain America", "Spectacular Captain America", "Friendly Neighborhood Captain America", "Peter Parker: Bearer of the Flag", and "Cap'n Spider-Flag Guy".