" Canon zoom lenses can only resolve 10-18 megapixels at their sweet spot a kit lens generally resolves 10 and an L lens or some high end non-L lenes resolves 16.5-18. Many Canon prime lenses also only resolve 18 megapixels."
Where are you getting these numbers?
As I understand it, the resolving power of a system is roughly:
1/R(system) = 1/R(sensor) + 1/R(lens)
Hence, increasing the resolution of the sensor without increasing the resolving power of the lens will typically still lead to an increase in resolution of the system until you've reached the point where the resolving power of the lens is severely limiting. If one does a simple plot of this equation (see below), that ends up being when the resolution of one component is an order of magnitude greater than the resolution of the other component. At this point, increasing the resolving power of the higher resolution component leads to severely diminishing returns. See plot below:
So what I'm saying is I seriously doubt Canon's lenses resolve anywhere near 10-fold less than their sensors... which means resolution increases in sensors even without new glass will still lead to increases in MTF.
I hope people remember that just b/c a pixel looks soft on a higher resolution sensor doesn't mean that the increased sampling resolution is useless or detrimental. A higher resolution sensor will always, barring other unforeseen variables, produce at least as sharp as an image as a lower resolution sensor once you've appropriately scaled both images to the same size.
That being said, I'm more in favor of higher dynamic range sensors & I'm hoping that the tradeoff will be worthwhile in the 1Dx.