How many of the "leaks" on the web are actually well-thought-out marketing? Do you really think that a company like Apple cannot keep their production lines sealed off prior to iPhone release (or at least force their workers to not carry cameras)? I think that leaks are a way of "announcing without announcing". I.e. test out customer response, keep customers loyal, while being able to miss targets without loosing face.
Now, actually announcing products early, that is another thing. To me, that seems like underdog behaviour. If you have a hard time competing, you need to throw in promises of future stuff to keep competitors back.
Why would Canon say that "soon(tm), we will have best-in-class resolution DSLRs", when they just released a "best-in-class resolution DSLR"? Beats me. If people really want more megapixels in 24x36mm, the 5Ds/R is the obvious current solution, noone else can compete. By saying that they will bump that sensel count by >2x within one product development span (?? years), they are basically saying to some potential customers "please don't buy our 5DsR now, we will do a lot better in a couple of years". That seems like a strange message?
Or is this a message about how committed they are to high-resolution usage of the EF line? "Buy the 5DsR now, buy a bunch of mk2 lenses and in a few years things will only get better"?
As a Canon user, I think it is great that they feel competitive pressure from Sony & friends. I'd rather have 5 manufacturers fighting vigorously over my money than one monopoly getting complacent.
-h