A pixel (currently) comprises a large surface with which to capture light. The way higher end cameras are going, there seems to be a fork between higher resolution (e.g. Nikon d3x or Canon 1ds-mkiii) and higher sensitivity (Nikon d3s or Canon 1d-mkiv). So yes, you can trade off pixel density for sensitivity, but in the end the per-area sensitivity would be the same.
The discrepancy here is did they figure out a way to make the sensitivity increase or just up the pixel density? It looks like (if you RTFA) they did make it a lot more sensitive, but who knows how much area the individual pixels will have to take up. The articles present the information as if both the resolution and sensitivity quantum leaps. Pun intended.