The Truth About Barack Obama:

[JoeH]

Do you know just how few Faithless Electors have existed in over 200 years? It would take more than have ever existed to change the results of this election. Much more than half were from before 1900, and nearly half were vote changes because the candidate for VP or President had died before the vote. So for all intents and purposes, it is a formality at this point.

http://en.wikipedia.org/wiki/Faithless_elector