I biked around 6000mi last year, but spread out among 3-4 bikes. I had at *least* 6 flats. I can't even remember exactly. When I am on my winter commuter, I actually rarely get one (1 1/4in tires) but on my bianchi's, and my ocr2 is the worst, I get them pretty easily. The roads around here also kind of suck. On a rainy day, if I brought my nice commuter by accident, its harder to see the potholes.
I have been pretty lucky lately, no flats in a few months.