They always sell a bunch of Death Ride slots the night before the event - and sometimes the morning of. When I wasn't able to ride DR last year (after velogirl and SK talked me down from the ledge), I sold my entry (for less than face value) at 5 am to some very grateful guy. I was just glad it was being used.
I think it is a good sign that rides are filling up. We are SO Lucky here with the number of great rides - heck we have over a dozen wonderful double centuries to choose from. More participation is a good thing.
Of course, I'm one of those somewhat anal peole who plan out what rides I am going to do at the beginning of the year and get my registrations in early. But with DH and I both riding, and needing to plan our schedule around our daughter and our TNT duties, we need advance preparation!