Also, while Intrade doesn't offer "winning individual" contracts yet, they are offered at Betfair:
http://www.betfair.com/
Current Betfair probabilities for the following people being elected president in 2012:
Obama 48
Romney 10
Palin 6
Thune 5
Pawlenty 4
Hillary Clinton 3
Daniels 3
Gingrich 3
Huckabee 3
That's funny.
I guess someone thinks she'll challenge and beat Obama in the Democratic primary.
Thune is doing very well, Gingrich not so much.
Maybe Thune/Barbour 2012?
Or more likely that he will not run. I think there is a chance, not a large one, but probably around 15% that he won't. In that case, Hillary would probably have a 70% or so chance of winning the nomination, and probably a better than 50-50 shot in the general, so if anything she may be undervalued.