For my needs and wants, a 7DII must offer two things over the current model:
Iso noise which is a lot better (I'm talking about a huge disparity between a 5DII and 7D) and the general per pixel image quality. When compared to the output from a 5DII/III the 7D was often left wanting. The rest of the original 7D is still very competitive and very usable...but anything over Iso 400 wasn't for me.
I loved the AF system, the 8fps, the handling, everything except the sensor...the most un-Canon camera Canon have made!