The Bradley effect is a myth. Like Truman v Dewey and the exit poll controversies in 2000 and 2004, the Bradley effect presupposes that the polling was accurate. In each case, it's apparent from the historical evidence that unreliable polling was the culprit. Just look at how much variation there is in the polls this election - the most heavily polled yet. A gubernatorial campaign twenty-five years ago can't even compare.
Conversely, there's the cellphone effect:
http://www.fivethirtyeight.com/2008/11/cellphone-effect-cont...
True. Both effects might true. However the 2 don't cancel each other out probabilitisticly. Given that McCain is so far behind the mere possibility of a Bradley effect favours him. Let's say both effects are 50% likely to exist and would sway votes by enough to tip the election. Then the results would be
25% Bradley + No Cellphone = McCain wins 50% Bradley + Cellphone = Obama wins 25% No Bradley + Callphone = Obama wins
So in this example McCain now has a 25% chance. Of course this is an exagerated example but hopefully you get the point.
It is indeed astonishing that no over is McCain a favorite to bet on.