It's my understanding that they won't let you know where you stand on the waitlist. It's sometimes frustrating, especially when you're trying to plan around where you'll be.
Call if you are on a wailist and check regulary. I have done this twice now and got what I waitlisted before the wailist came through. Mine was for a night or two, not the entire reservation, but it doesn't hurt. Just called MS this morning to add a day and they came back with the waitlist day available also