I debated for a bit on getting a 7D now or waiting for a potential 7D II - then upgraded to the 7D. I can't imagine much in the way of AF improvements in a 7D MK II, so the update will be either a lot more MPs with the same noise or around the same MPs with somewhat better noise. But IMHO, since Canon didn't improve the sensor that much between the 5D II and 5D III, I'm not expecting anything earth shattering with the next APS-C sensor.
And if some of the rumors are true, the next APS-C camera (70D?) could actually lose features and performance compared to the 7D. In that case I'll keep the 7D for quite a while.