I like my 7D, but do not love it yet. I was expecting high-iso performance to be better than my outgoing 40D but to be honnest it is pretty similar. On a per-pixel level the 7D has a very slight edge, but the extra 8MP's do a good job of making things seem better than they are. I would say the 7D is usable at iso 3200 vs 1600 for the 40D. AF is where the largest gains have been made and the 7D is much better at tracking small moving objects. The viewfinder is better, but that does not really help take better pictures. Sealing is sopposedly better but I have not dropped it in a puddle yet to test (my 40D survived the puddle test). The LCD is better, 8fps vs 6fps is better (but I never needed 6fps and have not even tried 8fps). Handling is the same. As for HD Video - I have a camcorder for that!
I know the 7D is a good camera, but it just does not have the same wow factor I experienced when I opened the box of my 40D. Perhaps the 40D spoiled me because it was really ahead of the game two years ago. The 7D just adds bells and whistles.
Oh, nearly missed out micro focus adjustment. This is one really neat feauture that has helped me get the best out of my slightly back-focusing EF-S 17-55mm. Setting MFA to +5 has removed the odd mis-focus I was getting with this superb IQ / average build quality lens.
Even though I got my 7D at a bargain £1060, I am not 100% sure it was money well spent. Even with pretty sharp lenses (EF-S 17-55mm F/2.8, 70-200mm F/4L IS) the final results are not much better than on my 40D. Most of this is probably due to poor user ability where even the 40D surpassed my skill.
So IMO the 7D is good, but not as good as the 40D was two years ago, or as good as many people suggest. DSLR's appear to be evolving at a much slower rate now, so maybe I will not feel the urge to upgrade for another 3 or 4 years. Manufacturers really should concentrate on IQ and high-iso performance rather than squeezing more and more megapixels onto a postage stamp. I hate to think how much glass will cost to get the absolute best out of such high density sensors.