It's grain of salt time - I'm considering buying a 10D, but haven't had a chance to play with one extensively, or anything....
What you have here is not a moire effect or something like that - you might expect to see moire in the bride's vail (notice how *sharp* the patterning is, there... wow, neat As I understand moire, it tends to happen in "high frequency" areas of the image - (excuse my lame attempt at explanation) ie areas with lots of lines next to each other or something like that. Test targets are a good example, for instance...
Also, notice how the frequency of the lines increases towards the bottom of the picture? Then there's sort of a break (just above the pendant on her necklace), and then a few more lines?? Do the other pictures you see this problem with exhibit the same pattern?? Can you post a red channel from one of those, just for comparison's sake??
To me, it looks like some kind of interference pattern, or processing artifact. Having never debugged this sort of situation before, I'd tend to suspect something in the realm of: faulty sensor, faulty in-camera processing algorithms, or maybe a little of both. If it's in firmware, it could theoretically be fixed w/ a firmware update.
Have you thought about running a couple of examples past Canon, and see what they say?? This doesn't appear to be normal to me (again, remember that salt!
Oh, BTW, nice shot!!! I've come back a couple of times to this thread to look at your picture