I went there last summer with a friend of mine. Very odd timing for us. It was bear week, but the Rosie O'Donnell cruise was also docked there during that time. So, during the day, the streets were full of lesbians pushing strollers. During the night, beefy gay men in chaps.
As for what to do, it would be too darn cold to do what I liked! (kayaking, whale-watching) The bike trails up in the big dunes are nice if it's not too cold to rent a bike. And if you want to pm me, I can tell you of a certain drag show that really sucked and should be avoided.