Funny thing actually, there was someone around a while ago, way back in the early days of the old forums, saying he was making/had some top-down maps and was wondering if I'd like them. I was going to get back to him but never did.
I agree, it is a good idea, I just don't know how to go about it. If you fly up too high the map gets clipped to shreds, and if you're too close, you can't see enough in a single screenshot, so you'd have to fly around, get a bunch, and piece them together. I think this is actually a lot more possible than I thought - evidently there's a button for go straight up in spec mode, so you could look straight down and press that. Anyway, then you'd have to do something about insides as well, and it all gets very tricky.
If anyone has a plan, I'd love to hear it. Oh, and welcome casale