I was admitted to Hastings after several months of being waitlisted. I did not contact them or send a letter of continued interest yet. So, I was pretty surprised. After paying the deposit last week, today, I withdrew. So, at least one spot has opened up today. Also, as other people are admitted to better schools, there will be a trickle-down effect and more people will be admitted to Hastings.
My view is that you shouldn't count on the waitlist, but you shouldn't assume it's hopeless either. A friend of my brother was enrolled at American Law, had started moving into her apartment, and the day before classes started at GW Law, they called her and admitted her. She started there the next day.