My bet: Huntsman resigns his post in the summer, frees himself up to campaign for GOP candidates in the fall, then forms an exploratory committee by year's end. He'll start out behind, and he'll have to deal with the baggage of being tied to Obama. But Huntsman, who worked in the Reagan White House and helped lead his family's global chemical company, brings a lot of comparative advantages to the table. He hails from a pivotal electoral region for the GOP; he is far more engaging and genuine than the flat Pawlenty and the flip-flopping Romney; and he can match if not beat Romney on economic policy credibility without his fellow Mormon's corporate-raiding baggage, which will be an issue in the post-bailout era. So expect him to at least be in the (ahem) hunt.
If this becomes true, it would be wonderful for the GOP. Huntsman is definitely a candidate that could appeal to "Whole Foods Republicans" and expand the party's reach.
Will it come true? We shall find out in the coming year.