I haven't read all the comments on this thread, heaven help me if I had that much time. But I feel like, after looking over the DXO info on the 70D, that Canon really hasn't advanced their sensor by a very great amount in the last 3 years, or since the 7D was introduced. From what I could tell with the DXO report, it appears to me that there might be very little noticeable difference in IQ between the older 7D and newer 70D.
Now that might be testament to the IQ of the 7D (although comparisons to Nikon's 7100 might temper that opinion some), but it also might be that Canon is less concerned with the IQ of the cropped sensor cameras, perhaps figuring--and possibly rightfully so--that those who are really concerned with IQ will probably go toward a full frame like the 6D anyway. So, with the 70D they focused on other features, and from what I can tell they did a fantastic job introducing new features that videographers in particular will be thrilled with. That was probably smart on Canon's part, as that is probably where they will see the biggest benefit from a sales perspective. How many photographers are going to upgrade from a 7D/60D to this new camera anyway? Many more videographers will, most likely.
I'm in the former group of photographers, I mainly shoot full frame bodies. I do have a 7D (and older 40D) just for odd things, which I was looking at the 70D to see if perhaps it might offer something that I would be willing to upgrade for. However, it appears there would be no real benefit for me to do so, as I'm not using these cameras for video. I will see what happens with the eventual 7DmkII release, but I don't really expect it to have anything that will really make me want to go there either. The 7D is a well rounded camera, as demonstrated by it's longevity and continued success. It looks like it will still be awhile before we see significant improvements with the cropped sensors, at least for photographers.