I can't find any reference to the direction of the Earth's rotation changing, but loads on the theory about pole reversal.
Thinking about it, the Earth is actually slowing down, due to the tidal interaction with the moon, which is itself slowly receding
However, the slow down amounts to days getting longer by 1 second, every 67,000 years, or so, but the moon is getting further away from Earth by less than 2 inches a year, so the effect will, presumably, attenuate.
http://www.physlink.com/Education/askExperts/ae201.cfm
Going by that, it will be a very, very long time before the Earth stops spinning - and no evidence for any mechanism that would cause it to start turning in the opposite direction.
Seeing as pole reversal will be extremely difficult to survive & is likely to happen sooner, I think spin reversal is the least of our worries.
