I'm still sticking with Hillary running in 2016. Usually after 8 years of one party, the other party gets in because the general population is sick of the same old thing. But if the Republicans have a lackluster candidate, or even a decent one, running the first woman for President (with a chance to win) will fire up the emotional and "white/male/rich/liberal/whatever guilt" vote.
Maybe the Republicans will pull a rabbit out of their hat, but right now I don't see any female Republicans that would be popular (or more precisely, more popular than Hillary) among independents and undecideds.
If Hillary doesn't run, then I predict that maybe the Republicans will smarten up and run Rand Paul, Jindal, or one of the other, more conservative and younger names being thrown about and will have a good chance to win. If one of these names is run against Hillary, I predict they won't do well.