I, for one, wish the 5d III had higher MP. I feel like the IQ will essentially be the same as the current 5dII that I own. ISO performance will be certainly better, and AF will kick serious but. However, it is a little curious to me that the MP as essentially the same. What I am saying, simply, is that the 1d3 and the 5dIII may be close to the SAME CAMERA!! Think about AF, frames per second, and MP. Then it becomes more curious.
Maybe I will keep my 5dII, which I am content with, and invest in new glass to be released soon. This may be my best bet. I just hate to keep a depreciating asset when I could afford to sell and upgrade for about $1,000--the price I would get for my D7000 that I never shoot. AF is not important to me because I do 90% landscapes. But I will withhold judgement until the "Official" release. We could be in for a huge surprise.