Frankly from my point of view, as regards what I look to see as the probable 2016 contenders in what would be the most unique and exciting campaign in US history, I hold a similar but reverse viewpoint.
I believe Sarah Palin is doing all she can for the GOP's ticket-given the obvious constraints she is under e.g. not being invited to speak at the convention in a major role etc. I do believe she is totally sincere in her "anyone but Obama" statement and exhortation, but frankly if Romney wins, it would be difficult ot envisage much of a future for Palin outside of the probably remote chance that she would be chosen by Romney for Energy Secretary.
If Romney wins, and the improving economic scenario as Votemaster sets out comes to pass, then Palin would not have an opportunity to run until 2020. The case often is that after two terms there would be a move back to the Dem's, so even if she had the nomination then, it might not be optimal (although she would still be comparatively young).
If Romney won and the economy did poorly, there would be the opportunity to challenge him 2016, but that is a hard row to hoe, and rarely a successful venture, as would be a third party run. Palin's best prospects are, I believe, the same as Hillary's-an Obama win in 2012, and a run in 2016 and may the best woman win (which is Palin in this case)
Here's The Votemaster's point of view on the matter.
Bill Clinton never cared much for Barack Obama, starting when Obama defeated Hillary Clinton in the 2008 primaries. But this year he is campaigning his heart out for Obama. Not that it takes a lot to get him on the campaign trail, but he is working extremely hard and obviously wants Obama to win. Why? He is a keen strategist and knows the economy is improving and if Romney wins, he will take full credit for it, even though the improvement is already in the cards, So if Romney wins and Hillary decides to run in 2016, she will have to face an incumbent President in a good economy, a very difficult task. Bill would much rather have Obama win and it be an open seat in 2016. That situation might create a primary battle with Joe Biden and others, but that is probably an easier path back to the White House than facing a sitting President.