The comparison is very simple.
Informative, but still nothing touching my major point. I was wrong to suggest that Nikon hasn't been consistent with specifications on its SLRs, like the AF point counts which have been remarkably stable regardless of the year or price (you'd think they could make it better as time goes on...but Canon has to catch up first, right?). On the Canon side my point is that AF module "downgrading" is only relative to other cameras in the contemporary lineup. By the time a 5D Mark III comes out, the 7D will be a year old. The 5D Mark II's autofocus sensor is similar enough to the original 5D's, and it's simply time for a change. The 5D line is apart from the "prosumer" or advanced amateur etc. lines, and it's separate from the 1D / 1Ds / 1.3x crop lines as well.
It certainly can use autofocus at least as good as the 7D, but in truth it needs to be considerably better than that. The 5D Mark III (or whatever occupies the line) really needs continuous autofocus in movie mode, for example, given the camera's use for filmmaking, which try as they might Canon can't sway users to the more expensive 1.3x crop cameras for. Unless Canon is hoping to aim people towards a new line entirely, or a different kind of product (like camcorders), they will simply lose a lot of friends if the AF system stays stagnant.
For what it's worth, the 7D's 19 cross-type sensors ought to beat (at least for photographs) the more impressive-sounding 51 point AF sensor-equipped cameras, when those like the D700 and D300S have 15 cross type. By the "Nikon only builds two tiers" theory, the D7000 is placed at the very top of the low end, with just 9 cross-type sensors, 39 overall. Not a bad argument given its price.
On the lower-tier cameras Nikon hasn't been shy about holding down costs - and cutting features: The Multi-CAM1000 AF sensor in the D3100, released almost at the same time as the D7000, has just 11 points, none of them cross-type. Even my poor old T1i has a cross-type sensor.