I reckon it comes down to how much one trusts opinion polling. It seems to me one takes a risk when you base your vote on reports of what other folks say they will do when asked by strangers (who themselves might be biased) over the phone about it.
Freegards
Well, it's not 100% about opinion-polling.
#1...we know which states went Obama in '08...though we know some of them will flip back in '12.
#2 We also know which states have been "POTUS-blue" -- and conversely "POTUS-red" going back numerous elections.
IoW, you don't have to be a "poll truster" to know that Utah will be safely in Romney's camp -- and that if 100% of FREEPERs voted for a third-party candidate -- that Romney would still easily take Utah.