Huckabee will be a force to be reckoned with in 2012, and adding a fiscal conservative Senator would rally the GOP, plus with the likely economic state in 2012 *high inflation, high unemployment*, Huckabee's economic credentials will be of great significance.
I actually think, if Obama's approval rating is like it is today (50%), or lower...a Huckabee/Thune ticket could be the strongest ticket out there.
Huckabee: 286
Obama: 252
(With 2008 EV)
I think Huckabee would sweep the upper midwest and great lakes with the help of Thune, and probably pull in other critical swing states...but not quite Pennsylvania or Michigan.