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.).
Let's be honest here - many of us, as consumers, want a FF camera with pro AF, enough MP for a decent 1.3x or 1.6x mode, 8-10 fps, excellent build, and priced under $3K. Could Canon build such a camera? I bet they could. Will they? Of course not. Their goal is not to make us happy, it's to make money and turn a profit for their shareholders. As such, they will fragment the market to the largest extent possible, so they have something in every price category yet leave room for people to aspire to the next one up the line. Have $1K - get an xxD, but not the best APS-C. Have $1.5K, get a 7D, best APS-C but not FF. Have $2.5K - get a 5DII, FF but slow and weak AF. Have $4K - get a 7D and
a 5DII, great combination, but then you have two camera to carry, or choose one to take out. Have $5K - get the APS-H compromise, some great features, but not FF. Have $7K, get the 1DsIV (hopefully, we'll see that next, please!) - it's the top of the line. But then you need longer lenses.