Canon is receiving quite a lot of bashing for not having the same low light performance as Nikon, and not so much appreciation for having higher resolution.
If you're a landscape photographer or studio photographer it seems to me that low ISO performance is key, and then resolution is an important factor. Some use medium format just for the resolution.
For my personal photo style, I'd rather go for higher resolution at low ISO and slightly worse high ISO performance. Needing large DOF and therefore often working around f/8 - f/11 which makes resolution generally diffraction limited I'd still could use as much as ~50 megapixels on a full frame sensor before additional pixels does not give significant value.
The exceptionally low noise at ISO100 in the sensor of Nikon's new D7000 shows that low noise (at low ISO) is indeed possible with small pixels.
However, if you need to shoot in non-ideal lighting conditions with short shutter speeds, then good high ISO performance is necessary of course. I don't really think that these conflicting goals can be combined into a single camera body today. Either you optimize for high res at low ISO, or low noise at high ISO. It's unfortunate that 35mm camera bodies are not modular as larger formats, then you could have two digital backs, one for high res and one for high ISO (and you could actually upgrade a body instead of having to buy yet a new magnesium alloy body).
Anyway, for me personally, I'm not particularly worried about the rumors of 5Dmk3 having as much as 32 megapixels, rather the opposite, it seems quite attractive to me. Closing in on medium format.
I also think the view on resolution will change in the coming years. Current resolution guidelines is based on more or less obsolete film and print standards. DOF calculators use acceptable resolution as 30 microns - meaning 1 megapixel. Saying that is a sharp image is like saying 8 bit audio is clear. In some circumstances yes it is true. However, not too many years from now we'll probably have monitors with 9000x6000 pixels rather than 1920x1200.