Wah... the argument is getting hot, and I shall harass the thread a little :devil: .
WHat I have observed is that Nikonians are defending the D2x and Canonians are building a moat round the up coming 1DsMk2 as well. But who can blame ? Thats human nature to defend something you consider dear to you. I have even thought my VW Golf is better than a V8 muscle car, just because it drinks so much less.
I'll give me 2 cents worth... in the area of FF vs APS sensors. I once drooled over the 1Ds FF sensor, simply because I love wide angle. But I've given this subject much thought, and I have decided that APS sensors may actually be beneficial to certain areas of photography as well. Nikon and Canon has solved the wide angle problem with top notch DX/EF-S lenses. That provides canon with 16mm at the wide end (35mm equi) and 18mm for Nikon. And this in my opinion is enough. It is true that the SIGMA 12-24 would give a FF camera a 12mm focal length, but honestly...... only a select few would choose to shoot this wide. So basically, the wide angle aspect has been pretty much solved in APS size cameras.
Now, let bring the telephoto side of things into the picture. WIth a D2X, a 500mmf4 lens, "becomes" 1000mmf4. With a FF, 500mmf4, is 500mf4. But given the resolution in the 1DsMk2, you sure can crop... which is even better because you can choose to compose your picture in Photoshop, with room to spare. But shooting speed is compromised in a 1Dsmk2, as compared to the D2x, which may prove crucial in certain aspects of photography.
If APS sized sensors, can provide the same quality and resolution with a FF camera in future (which is probable), I may be at a fix which way would I go. FF or APS.
Someday, I would think, it may just voice down to which lens is easier and cheaper to manufacture. A wide angle DX/EF-S (which there is already a solution), or a high speed super tele. I would think, a 10-22 or 12-24 would be more easily attainable, than trying to build a 1000mmf4 for a FF, when it "only" takes a 500mmf4 in an APS SLR.
This leaves my comment open ended........