Now that dpreview has reviewed the NEX-7 and said "It's no stretch to say that, at its best, the NEX-7 offers the finest still image quality of any APS-C camera, bar none." it is going to be an uphill battle for any other APS-C sensor camera to sell well against the current Sony lineup. That sensor is in the SLT-A77 ($1400), SLT-A65 (~$900) and NEX-7 ($1200). If Canon wants to sell into that part of the market to new customers then they're going to need to offer something that at least on paper has the same MP count because the "more MP" of the new Sony cameras is not "less IQ." We should assume that Nikon will have access to the same sensor and that it will show up in Nikon cameras next year too. 2012 could be very tough for Canon without a 24MP APS-C sensor. For the 650D/T4i not to be a flop, it will need to have 24MP. That's now the megapixel entry point into the DSLR market at $900.
It would be interesting to know who's more important to Canon - the new customer who is yet to buy into a brand or the existing one. Which offers more future scope for sales? If you've got a 60D with a couple of L lenses, what's the chance of you buying new L's vs a new customer? Or if the 70D comes out at 24MP, would a 60D owner dump all of their existing gear (and at what price?) and go to a 70D + new lenses or just upgrade the body? And so on.http://www.canonpricewatch.com/price-changes/