Re:Maybe not. (Score 1)

As a professional photographer, I have to chime in here.

Just because Canon can put out sensors with higher density doesn't mean it does a bit of good. Even the high-end SLR lenses from Canon and Nikon don't have the autofocus accuracy or resolving power to get per-pixel sharpness on dense sensors. Slight camera shake (even with stabilization) translates to slight blur. To get sharp 1:1 crops on hi-res sensors, you need a big camera with a big sensor and a big lens on a tripod.

The real frustrations for professionals and consumers alike are:

1. Noise in low light
2. Dependable automatic white balance
3. Wide dynamic range (aka HDR)

Low light performance on full-frame SLRs is really getting good, and has pretty much exceeded film. White balance accuracy is pretty much staying even. The dynamic range of digital is still nowhere near film, but improving slowly.

Getting to 24-bit/pixel dynamic range will pretty much take care of the other two problems. The current best for DSLRs is 14-bit, and on (tens of thousands of dollar) medium format, it's 16-bit (so far as I can tell). Those medium format cameras are at roughly the same sensor pixel densities as the 21mp 1Ds Mark III, probably because pixel density is one of the biggest factors that contributes to noise.