The 1Ds MKII isn't really about increased resolution, as I pointed out in my review. Yes, the jump from 11MP to 16MP is a 23% increase in image area, but that's not what the camera offers as its main advantages.
The big news is the handling. The MKII is fast, almost instantanious and intuative in its responsiveness compared to the 1Ds. It also has about a one stop improvement in noise, so that ISO 800 looks like 400, and so on.
The rear LCD is much brighter and higher res, and the RGB histogram is very welcome.
Anyone looking to switch to a MKII just for the increase in resolution is missing out on what's really of greatest importance.
As for lenses, I use all of my zooms as well as primes. The point of photography is to capture meangingful images, not to count lines / MM. Buy and use the best lenses that you can for the type of shooting that you do, and then concentrate on image making, not technical analysis.
Michael