I've been doing attack, combat and pump for about 3 or 4 months now, and I'm loving every minute of it. Sometimes, it's the highlight of my day, getting ready to work those muscles and get fit, while enjoying great music and having fun.
I think the degree of interest, in terms of choreography also depends on what instructors make it. I think the first post here mentioned the running, clapping in a circle, then pendulum legs, etc. and I admit, it sounds kinda mundane, but our instructor makes it really fun with her general happy enthusiasm, which infects us participants.
I think the enthusiasm of instructors is really important in motivating participants, and I enjoy my sessions every time, partly due to my instructor's awesomeness :)
Combat: Attack: Pump