Canon's 5D MK III is all set, and Canon knows what the Nikon d800 will be. The only question in my mind, is will Canon resist the temptation to pile on MP, or do something more modest. Those samples of D800 images at higher ISO's look horrible, hopefully, they were from a prototype and will be much better for a released product. Right now, Nikon fans are really screaming on the Nikon Forums.
Maybe the D800 isn't aimed at the Nikon fans, but at the Canon fans (there are more Canon cameras...) who have bought the 5D2 over the D700, meaning that more customers value more MP than more IQ...
Its always possible that the images were planted, just to see what the response was, and that a backup plan is in place.
You mean that the leak of the images is deliberate for lulling others (like Canon) into believing the upcoming D800 IQ will be worse than it really is?