If AF is only thing that will be improved in 5d3 there would be nothing keeping me in Canon. I expect a big step in DR, AF, ISO. I have already decided, that if that would not come, I end my relation with Canon. I was a Nikon user a year and ago, and switched to Canon, expecting next 5d3 will be outstanding, but so far it seems that my old friend Nikon made a camera that meet all my expectations, even a little bit too much (mpix). I am little bit upset about Canon, however we will see if there's a really a new nicely improved 5d3 coming or only an old one with a perfect marketing around and better AF. Hope the first option will be valid, because selling my Canon lens would be a financial loss for me. To be honest, after I had bought a 5d2 a always waited for 5d3, i did not like the camera, I was being used to AF and other things in Nikon like WB, colors, configuration options, built quality, raw files. 5d2 images was better in terms of quality but i just hated capturing things with 5d2. People who own s Nikon know exactly what I am talking about. Bought 5d2 it for Canon primes and other lenses. Right now a 5d3 will be a kind of decision maker for me. Stay or go away. I know, i know- i write it many times, but I am really frustrated with Canon and made a bad decision about year ago.