Four DSLRs are not hard to imagine:
Entry-Level Full Frame (Rebel FX?)
Canon seems to have a dilemma with the 60D. Its price and specs are too close to the t4i. The upgrade path is pretty clear: put the features of the 7D in a composite body with a swivel touchscreen and call it good. But, what does that do to the 7D? The body alone might be enough to protect the 7D for a few months, if the 70D gets the same 18mp sensor as the t4i. But, that's not a long term strategy.
I can see Canon deciding to release the 7DII and 70D in tandem. Both get a new sensor. 7DII is essentially a 5dIII with an APS-C sensor. 70D is as described above (7D features in 60D body)
5DHD (High Definition) is identical to the 5DIII (including price) but uses a 46mp sensor (essentially an 18mp APS-C sensor upsized). Canon has three years' experience with the 18mp sensor, so they can put what they've learned to work in a high-resolution 5D without risking any unpleasant surprises. As long as the sensor is the only difference between the bodies, production costs are minimal and there is little risk that one body cannibalizes the other. They just switch out sensors on the production line depending on which model they need the most of. You want low light, low noise -- buy the 5DIII. You want high definition -- buy the 5DHD. What does Canon care? They get your money either way.
That just leaves the "entry" level full frame. What that looks like will depend largely on what Nikon's comparable model looks like (if it materializes). I'm guessing something in a composite body, swivel touchscreen, scaled-down or recycled 5DII autofocus, SD card only, perhaps no micro-focus adjustment. If Nikon produces a more full-featured body, the specs may be improved to compete.
70D – Not sure. Needs to be above the t4i, but not too much above to encourage potential buyers to "step up."
7DII – $1,600 - $2,000
5DHD – $3,500
Rebel FX (full frame entry level camera) – $1,500 - $2,000) like the features, pricing may be determined by Nikon's offering.
I can hear the cries now: "You can't price the 7DII and a full frame Rebel so closely!" Of course you can. Some people want the perceived advantages of the full frame, others want a fully-tricked out DSLR with a 1.6 crop factor. Both markets are sufficiently sophisticated to know what they want.
Oh... and one more thing: Canon is no doubt watching their 5DIII sales figures. If they decide the $500 difference between the 5DIII and the D800 is costing them sales (not sure it is), they may make a minor price adjustment (I'd guess around $200). They might then offer registered 5DIII customers a $200 rebate on any "L" lens as a loyalty reward. (Which, of course, also boosts lens sales)
Just remember. You heard it here first.