The thing that most people don't really talk much about when writing these things, is... a lot of us already have cameras that were like the 5D2, D700, 1D series or D3 series, etc. Higher end cameras. And also a ton of amazing lenses for either Nikon or Canon. Switching isn't cheap, it's not easy for most of us. If I really wanted to switch to Nikon (I don't want to), it wouldn't be so easy. My 35L, 50L and 135L won't sell for as much as brand new, and the Nikon equivalents are more expensive. Also, my TS-E and 100mm macro, same thing there. So I'd be losing money on lenses, big time. And same goes for Nikon users.
Is the resolution bump, something the vast majority of people have no need for, or practical application for, worth switching everything over? Is the snappier AF and better clean ISOs and better video of the 5D3, or "sexier" lenses of the Canon line up worth switching over for? It's totally not. And I suspect most people who boast they're gonna swtich, aren't. And most of those people most likely have absolutely no need.
After all, almost all of these things will not make our photos better, our creativity and vision have very little, or nothing to do with it all!