There is extremely strong scientific evidence that circumcision mitigates the risk of contracting certain STDs and eliminates the risk of certain, well, penial-issues like problems retracting the foreskin.
But I think the debate over circumcision rests mainly on the fact that you're making a permanent change to the kid before it's able to properly understand what's going on. There are potential side effects associated with circumcision, and you are removing a certain amount of sensitivity and nerve-endings by removing the foreskin (although a lack of sensitivity is usually the last problem dudes have in bed).
It's kind of a complicated debate, but I don't think it's appropriate for the heavy anti-circumcision advocates to compare it to genital mutilation when that's obviously not the case. The vast, vast majority of circumcised people have absolutely no issues, and the resistance to STDs might even make it a net-positive procedure.
I'm cautious about some of the research being done when there's such a cultural bias in western society towards circumcision. This can affect the validity of the results, and I haven't read any of the studies close enough to see whether the methodology is up-to-snuff.
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