We (the staff) actually meant to have cosplay first-aid available this year, but it kinda fell through due to not having a definite plan for which department could take it on.
Having cosplay first-aid available at Info Booth is a good idea, and I think it's worth looking into. The only thing I'd be worried about is the crowding factor - Info Booth was a lot busier than expected this year, and cosplay repair can easily take a few minutes of time. I'd hate to see people rush and stab themselves with a safety pin, burn themselves with a glue gun, etc. But at the same time, I'd hate to see a long line of people who just want to know where registration is build up behind a cosplay repairer.
If you're thinking about a booth that does more-than-first-aid cosplay repairs for people (and letting the repairer charge for their time and expertise), that's a really nifty idea. It'd be well worth asking the Artist Alley manager about once we do staff signups. (Officially speaking, we won't have a 2012 Artist Alley manager until then.) But please keep in mind that no matter how good an idea is, it will never go anywhere unless it moves beyond "Someone should do this" into "I will do this".