Well, I just sprung for the breathable-waterproof pants. (Made the purchase online before this thread began, alas.) They arrived yesterday. They appear to be very well made, and the cuffs are perfect for cycling. But they do look, well, heavy. I guess that's par for the course with breathable/waterproof fabric. It hasn't rained yet, but I doubt they'll come out in temperatures above 40 degrees.
But to those who think breathable/waterproof is a myth, I direct you to the Mountain HardWear Synchro jacket. Through all the driving rains of last winter, it was amazing.
http://www.mountainhardwear.com/Prod...&viewAll=False
Perfectly waterproof, and breathable in those winter rains. I figured that maybe somebody could do pants like that. We'll see.

EDIT: I don't work for Mountain HardWear! I never endorse anything; I hate all branding. I cut the logos out of my clothes or black them out with Sharpies. But this is a good product.