" AF we have discussed to death - most 5DII users seem to find it OK - it works happily in most situations and is still the best in class in low light "
Well that is a ringing endorsement, most find it OK! And they are the owners, not the most unbiased of respondents, the 5D was constantly criticized for its AF performance, everybody took a deep breath when the MkII was announced with a slightly improved version, people have just got used to how bad it is when compared to regular use with a much better system. As for best in class, that is a claim that could only be supported by people who don't use the 5D MkII and the D700, it is just not true in real world use. Wait a bit longer? For three full years, over 36 months, prosumers have had a vastly better option for AF than the 5D MkII.
I might be the minority here, I am a stills shooter, I paid $6,000 for a camera that doesn't have video, it is of zero interest to me, I paid that primarily for the AF. The 5D MkII was a groundbreaking camera with an amazing sensor that will not be truly outclassed for years and years. People will be taking amazing images with them until they can no longer be repaired or get batteries for them, but that is despite the AF, and just because it is "good enough most of the time", doesn't mean others solutions are not better, cheaper, more feature rich in whatever area the particular owner needs etc.
Don't make excuses for Canon, kick them up the butt, don't fawn over new mild upgrades that are vastly over priced. Tell them what we need, sure the 8-15 is a fun lens, but how many circular fisheye images are published? Yet again it is a small sensor video orientated lens. An improvement of the 15mm prime with USM etc would have been a much better idea for still shooters.
I have downloaded the sample images, in Lightroom they look absolutely fine to me, the detail in the library shots is remarkable, compare the portraits of the D800 to the D1x, don't repeat what "has been reported" look at the stuff and make your own decisions.
Nikon have made a remarkable comeback from tragedy, disaster, and devastation both in Japan and Thailand, Canon had, by comparison, a better time of it, what did they do with that time? A $10,000 video camera, four $40,000 lenses, several lenses that have yet to see the real world and a belated 5D MkIII that might equal, or slightly best, or not, the already announced, and downloadable sample images from their competitor that was two generations behind and knocked to their knees not long ago.
Sure Canon cameras "are good enough", Canon corporate performance for stills shooters is not.