http://www.kenrockwell.com/canon/7d.htm
INTRODUCTION
The 7D has not yet been announced.
I expect it will be announced August 22nd, 2007 to replace the aging Canon 5D.
FORECAST
The 7D is the 16MP replacement to the 5D. It will use the sensor from the Canon 1Ds Mk II in the 5D's body. It's a full-frame 24x36mm sensor.
If you have something to shoot today, get the 5D since the rebates make it cheap - about $2200 if you get a lens and take full advantage of Canon double rebates. See obsolescence for more. The 7D will come in at $3,099.
It has a greatly improved 3.0" LCD. It creeps up to 3.1 FPS.
It adds Auto ISO and many of the little ergonomic necessities it's lacked compared to Nikon.