Update: If anybody cares, I took the first class today...it was a pretty incredible workout, I am already sore and am not sure how well I will be able to walk tomorrow. Overall though, it was pretty fun, and I am definitely going to go back next week. While it was very basic, I am, uhh, much better at kneeing people in the head and abdomen than I was this morning. The instructor was this guy Phil Nurse, a former several time world champ. He was demonstrating some stuff on me, and I learned that I would prefer not to ever get kicked in the head by him at full strength. If you're looking for a different twist on your workout besides the treadmill/elliptical runner/weight room, I'd recommend checking it out. They start you off pretty slow, so it's not that intimidating.
Ask Phil about the conditioning routines he goes through to TOUGEN up his shins and elbows. I remember a friend of mine that to used take Thia Boxing...he had shins/elbows of wood. Or at least, almost as hard. I'm always amazed of the conditioning those guys go through!
Oddly enough, I went to a Muay Thai match on Tuesday night at Lumpinee Stadium, downtown Bangkok...ringside seats for $40. The concierge at the Oriental scored me some. I never thought much of kickboxing before that but after several Singhas and watching some great bouts, I dig it.