TBH though, I personally think its a bad move. I think everything should be going to full frame...
But then they would be ignoring a *huge* installed base of EF-S users.
I think that really depends on the audience. If you want to support all of the EF-S lenses out there, you design for it. If you want to come up with a product that gives people incentive to buy and/or upgrade bodies and lenses, you build for EF.
The people who buy up all of the EF-S lenses aren't upset that the 1D/5D won't support it because those cameras are out of their league and/or price range anyway.
IMO there are two classes of DSLR users, those who know/want the benefits of Full Frame, and those who don't. Most of the "photog" friends of mine don't have a clue what I'm saying when I mention that I'm disappointed the 7D wasn't FF.
Also IMO, what would be a HUGE mistake is if they made the APS-C bodies no longer compatible with EF lenses. That would pretty much kick any sort of upgrade path to the curb.
That said, I'm a HUGE fan of FF. I want it desperately, but I'm buying the 7D. I'll probably regret it when Canon releases a FF with all the same features for only $1000 more, but that's what you get with technology.