Then again there is a problem, if a "cheap FF" will be born at 7D's price point, it could be "the end" for the 7D. I wouldn't buy a crop camera over FF for the same price. Would you?
Yes, if I needed better AF and a faster burst mode
but you're right: that may be a relatively small market
Canon isn't foolish - they'll want to keep a high-end crop camera. Lots of people upgrading from a Rebel/xxxD or an xxD will have EF-S lenses, and they've shown there's a demand for a top-of-the-line in the APS-C segment. The 5DII AF is already a handicap. If they release a 'cheap' FF camera, it will have many handicaps compared to the 7D line (not just a weak AF, but likely xxD build, probably only 3 fps, etc.).
I think the 7D also has an important place for wildlife photographers. I don't have a lot of experience with shooting wildlife, but I would say that the 7D makes a good choice for working on foot in areas where you have to carry everything, including your tent on your back. Canon will need to keep a high end APS-C camera to compete with Nikon and Sony.