This type of 'X did really well, convert everything to X!' can really hurt a product line long term.. if they are not careful their whole line will become 'video, some with still capture capability'.
If they are not careful...but I think Canon is pretty well tuned in to their markets, and I doubt they would make such a major mistake.
I have a slightly different take, that Canon is pretty well tuned in to its accounting needs. It knows that DSLR sales are slowing after phenomenal early uptake, and that improvements are now incremental rather than the massive leaps of earlier days. This is why I believe that we are seeing huge price increases on new like for like products, I also believe that the materials being used are cheaper than those they replace, (plastic bodies replacing alloy on long lenses?).
Hopefully the 5D MkII replacement will address those shortcomings that almost everyone complains about, especially the autofocus, and for that reason alone I think the replacement will be a big seller, but it might well be the last one that is. I am hearing a lot of Nikon users saying that they are not going to upgrade to the D4, still more have concerns over the file sizes which will result from a 36MP sensor in a possible D800, so large that stock libraries will not accept them without downsizing.
For me I'd upgrade from the 5D MkII if the only change was a decent autofocus (providing it doesn't cost the earth), anything else is a bonus, 21MP is enough for all the applications I have and if I really really need more I can hire a MF camera. 22MP would be a nice size, particularly if noise & dynamic range are improved.
