Why would they bring out a 650D, when the 60D is less than 18months old and still selling well?
The new 7D will come out before the new 60D, as the new 60D will inherit the new 7D's sensor etc, and the 7d is older.
The 600D is even newer than the 60D, so apart from the 7D (and the new 5D MkIII), I think Canon would only bring out a new DSLR into a new category and not to replace any current models for the time being at least.
I could understand that Canon would bring out a mirrorless camera, using the new sensor from the GX1 and the ability to use EF-S lenses, as this would be a great idea for Canon and would give them an instant large range of lenses for the new mirrorless camera, but I doubt they will bring this out for another year or so, so that the GX1 can get some runs on the board first.
Maybe they will bring out the mythical 4000K video camera?
The XXD bodies have come out every year like clockwork. They are aimed at beginners who are seen as very sensitive to wanting the very latest model, even if the only difference is minor, they are often not into fussing over fine details.
There are always a few new things to play up in a new model. They have to do it, because all the other players come out with a new model each year.
The 60D is kind of a oddball. Canon downgraded the XXD series to create a differential with the 7D, and now, the XD and XXD are too close to each other.
I think Canon will raise prices to spread out the products, maybe $2K for a 7D MK III and $1400 for a 70D. DSLR's are selling very well, so they likely think they can bump prices. However, they have to stay competitive with Nikon. Competition is good!