agree with 1336--if there's a disagreement the default should be to the decision that can be changed based on need or your son's preference. for us, I was strongly opposed, DH was kind of for it.
Without getting into the debate to do it or not (or what the right answer is), which this thread will likely turn into, here is the way I approached it: I opposed the "look alike" argument with logic (are you really going to compare penises with your son with regularity) and stats--the number of circs in the US is declining and about 60/40 so he wouldn't the only one. for medical: I argued there was no medical organization that endorsed it, we will teach our son safe sex habits, and if he needs it b/c of excessive UTIs, then we'll do it once there is an existing medical need. Also, I indicated that the risks may be minimal, but there are risks and I didn't think we should expose our son to them without medical need or overwhelming consensus. So we didn't do it. FWIW, my son is 4 and hasn't had any UTIs or problems. And my DH hasn't not mentioned it since we decided so obviously not plaguing him. One day I'm gonna tell my son he can thank his mom for standing up for his penis, I'm sure that won't mortify him at all!
Also if you feel strongly, you could let your DH get his preferred approach on something else that you haven't reached a consensus on: middle name for example.