I've already switched part of my kit to Nikon - the Nikon D800E. And I may consider switching entirely from Canon to Nikon if they bring out a high spec pro model based on the 36mp sensor. I'm beginning to lose faith in Canon's ability to produce cameras that I want to use, even though I've been a Canon user for the past decade.
Despite the hype, the Canon EOS1 Dx is clearly a sports camera. I suspect that Canon has had a much higher pixel count camera in development, which for some reason, has failed to materialise. The decision to hype the 1Dx as the new flagship body has clearly been a desperate ploy designed to buy time to find a replacement.
In past I would have stuck with Canon though thick and thin, but also because I had invested so much money in Canon glass. However, new high MP cameras are showing up the flaws in old lens designs, so we'll have to replace our lenses with new one anyway if we want to up grade. Therefore, being tied in to a lens range no longer applies.
I do hope Canon get their act together soon. The EOS 1DS Mk III was and still is a superb professional camera body. However, if Nikon bring out the rumoured Dx4 in the Autumn, with fast processors linked to the 36mp sensor, Canon are dead in the water. Everyone will jump ship. And once they have invested in Nikon glass, they're not going to change back again for quite some time, regardless of what Canon does later.