I was on the first DVC Member Cruise in 2003. The day they opened for booking, most categories of rooms sold out. Waiting lists formed. I got in on the first hour and secured our category 6 cabin, our first choice. Little to no chance of it not selling out I am afraid.
Why don't you hop over to our DVC Board and consider buying into it? Sounds like you have an interest in DVC, and that way you could have a chance on the member cruise, perhaps?