it seems to me there might be some usefulness to a lot of pixels with some cleverness -- improved dynamic range per Fujii, pixel binning at high-iso. granted, Canon hasn't shown particular interest in cleverness so far, but we're getting pretty near the manufacturing limits for 35mm lenses with the latest offerings from Canon, Nikon, Zeiss, and Leica. pixel density for pocket cameras have (fortunately) hit the wall. my s90 gives quite good RAW results in good light at base ISO, but the overall IQ is not much better than 2 or 4 year old pocket cameras with lower pixel density.
i'm concerned that SLRs continue a pixel race that results in no practical benefits. as much as i like the features of my 7D, high ISO is no better than the 40D and practical resolution is only incrementally better - both significantlly less than the 5D2.