I'd just like to point out that this is being posted by somebody with skin in the game, who would have respected the Canon engineer's wishes if he had asked them not to leak the information out of respect (though that would've reflected sloppiness on Canon's part, so their honesty is refreshing and our respect well-deserved in this matter). We have gotten pretty used to the "father's brother's cousin's nephew's former roommate" rumor mongering without anybody having any skin in the game besides CR. So CR Guy does pretty well sorting out the true and the false so we don't have to, but this is a totally different thing altogether.
Does it matter that somebody had to leak the Nikon D800 (supposedly, still) with missing labels and so on? Not really, that's just business as usual. Of course you have to consider the possibility that Canon had considered (even perhaps wanted) these photos could leak, and of course they have greater control over what's going to be said, because news outlets are under NDA and all we see are a couple pretty lenses and a nice-looking camera - no hesitant sentences in a preview to mull over. It looks good overall, however.