Hi,
Auto focus for F8 is actually quite importance especially for those who shoot birds. A lot of birds are quite small even using a 600mm and lots of birds won't let you go near. So many bird photographers who own a 500mm/600mm and 1D DSLR usually also owned a 2x extender, so they might not upgrade their DSLR. Also, if 1DX cannot AF at F8, the lens that can use the 2x extender will be limited to those f2.8 lenses. By looking at the 2x extender description in Canon website, it's obvious that the 2x extender is design to be used on super telephoto lenses which most of them are at F4... so I was quite surprise when I heard that 1DX cannot focus at F8.
By the way, his next sentence is also important, again, given the same sensor size and print size.
Oh, and more pixels does not - now, in the past, or in the future - mean more noise. Just to bury that notion before it comes up.
Ok, I still need a bit of education on this one, so be gentle:
In that case, why did Canon reduce MPix to 18MPix for their ISO-demon, the 1DX? If pixel count is irrelevant to noise for a given sensor size, then why not jump to 30+ MPix? That would sure have pleased more people....
I have some difficulty believing it was just to get the frame-rate up.
Technically, 1DX is the replacement for 1D4, so the MP is actually increase, not decrease.

Anyway, I think the frame rate might be one of the major limitation that limit the MP in 1DX. How big is 1DX 18MP RAW file going to be?? My 60D (also a 18MP DSLR) usually had a RAW file of around 22MB. So if I assume that 1DX RAW file is going to be around that size, at 12FPS, you'll need to store 264MB of data in one second. If 1DX using 36MP, the RAW files size should double and you'll need to store 528MB of data in one second. So let assume that 1DX had unlimited internal memory and we use a 100MB/s write speed CF card to shoot 12FPS for 1s and how long we need to wait for all the pictures in the internal memory to write to the CF cards:
1) @18MP:
Total data = 12FPS x 1s x 22MB = 264MB.
Total time wait = (264MB / 100MB/s) = ~2.6s
2) @36MP:
Total data = 12FPS x 1s x 44MB = 528MB.
Total time wait = (528MB / 100MB/s) = ~5.2s
Just wonder how many people will wait for 5.2s in order to get the card out of the DSLR after shooting 1s(@12fps) of photo without curse and swear and how many people can afford the 100MB/s write speed CF card??

Just my $0.02.
Have a nice day.