My thinking on the subject is that the Canon "x"d line is going to be full frame only in the near future. Instead of updating the 7d to the 7d Mark II, they established a new line to carry on this traditional standard when they made the 70d. That is the new high end enthusiast level Sports / Wildlife camera. In a year or two they will bring out a 70d Mark II that will be the camera everyone is expecting as the 7d II.
Now the question is what will they do with the 7d line? To be a full frame that is an upgrade of the 7d line, it would need to be faster, 10 fps (my guess) and the ISO ability of the 6d. As for the resolution, it will likely be somewhere between 16 1/2- 20. That is my guess what we will see. Because that is what I expect, I assume the timing on the release on this "new" version will be after the sales of the Canon 1dx start to slow way down due to everyone expecting a new version of that camera to come out soon.