It appears to me that Canon rely heavily on economies of scale and when they release a major update(certainly in their minds) like the 5Dmk3, there has to be a reasonable product life length.
On the surface other makers seem to be a little bit more reactive to other brands product developments and are releasing newer models quicker.
I don't think Canon are falling behind, they are committed to what they have got and unfortunately they are behind. Certainly in expectation and certainly at the 36MP standard.
And I think 36MP or better will be the standard. If Canon don't come to the party, more will leave. And what should be even more of a worry to us loyal Canonites is what is going to come after the D800. I have never gone to the other brand fan sites, but I think they might all be craving for what is going to come next as well.
If I had more commercial needs driving my photography passion I think I would have brought a D800 into the stable by now, just to keep up with the results that portrait shooters are getting with it.
I think the 70D is a sensational development at the price and the features(video) and the 1DX has sport and bird photographers satisfied.
But I am hopeful that the next Canon development is earth shatteringly good, but aimed towards portrait and landscape shooters, who have been left behind by the developments of other brands. I am hoping for around 40MP, low light and dynamic range field leading performance and to top it all off not a medium format price tag. With the D800 and the a7r at just over $3000, if Canon don't play in this price ball park, or near enough to it, I think the Mk2's from those brands will blow the socks off Canon.
You know it's funny. Funny like a dual edged sword, which isn't funny.
While I look to the stars and am so grateful for the quality of all my canon glass. I am also starting to feel a little trapped by the huge investment I have made in this glass.