My 2 cents.
I have been shooting with a 50D and L lenses. Went on safari to Serengeti last march, and am planning to go again in August, 2012. Last trip, I borrowed a 5D2 and used both cameras/lenses. The 5D2 was superior in almost every situation. Many times I used both cameras to take the same shot with the same lens just for comparison purposes. Once back, I evaluated the pics on the computer and decided on getting a 5D@ of my own.
Subsequently, all the hype about the 5D#, so I decided on waiting. And I waited, and I waited. I won't go into all the issues of mp's, focus, 7D, 1DX, etc. Finally the price dropped, AND they are throwing in CF cards, bags, and software (? value), and I decided to pull the trigger.
I am aware that a 5D3 may be announced and ship tomorrow, but no regrets. If it does, and if the specs and performance are appealing, I will find a way to get one before my next trip. In the mean time, I want to get proficient with the new camera so that when it really counts in August, I will get some shots that I can be proud of.
If I won the lottery, I would be on the 1DX list, no question- but then, I buy the tickets, but don't win.
Hope this helps.