With regards the sports shooters choice, Mikael did make a good point, the Beijing Olympics was a low point for Canon and the terrible job they did with the AF in the 1D MkIII. He then posted an image of one session at the swimming pool. Now I don't know how many here know how the photographers allocation goes at events like this, but if it isn't a blue ribbon event then the photography pool could be made up of people as low ranking as me, a secondary shooter for a national (very small nation) paper. A picture from one event can look very different to another event, and a crop can be made to show anything.
Now the top event, the actual kill to even get in the lottery for the "free" allocation to get the worst seat in the press section, is the men's 100m final, to get an accurate count of the white to black lenses that the best of the best in that field of sports photography are using, you would need a panoramic image where you could see almost every photographer covering the best vantage point from the mens 100m final at Beijing, the worst Olympics in recent memory for Canon.
Anybody that interested could do the count here
http://www.karikuukka.com/peking2008/100m/
Certainly the combination of the 1DX and MkII teles superior AF is winning a good few back to the white side.