I too am a bit concerned about 18MP in an APS-C sized sensor. Very concerned actually.
I enjoy the 10MP range of my 40D. I'm sure the new features will make this a good camera to USE, but I hope the IQ can live up to its other features.
There is a lot for me to like as a full-time shooter, the 8FPS jump would be great for my sports shooting. Also, in all honesty, I would greatly benefit from the video ability. I shoot a lot of video with the 5D2 and having a second body with a bit of extra reach would be great!
I would prefer to have another 1Series camera, but honestly if the final spec images are good enough. I'm going to seriously consider one of these guys.
I think the 5D2 + 7D combo is going to be very popular amongst us FM'ers