
In my opinion, the 7D showed Canon's commitment to the 1.6x crop sensor, and I figured they would have released some higher end EF-S lenses by now. But maybe I'm totally wrong on this, which would explain why they haven't.
I feel the same way. I was really excited when the 7D turned out to be APS-C because I thought that it would mean more quality EF-S glass, but instead we've gotten a $1500 f/4-5.6 telephoto and a $1400 fisheye zoom that is practically usable over only part of its range for APS-C.
An update of the 17-55 f/2.8 to a 15-50 f/2.8 to give a bit better wideangle plus a 50-135 or 50-150 f/2.8 would make an outstanding, relatively lightweight combination. Throw in an EF-S 30/1.4 and I would be a happy camper.
Rumors suggest that Panasonic is going to release a 12-50 f/2.5-3.3 zoom soon. That's a pretty fast zoom and is equivalent in focal length to 24-100mm on full frame. They're supposedly also going to have a 25/1.4 soon too (equivalent to a 50/1.4). With the autofocus and ISO improvements in the GH2, micro 4/3 is looking more like a really nice, lightweight alternative every day.