65th is really good, it's one of the highest positions on the list I've seen so far.
It's almost impossible to say what 'chance' you have at getting in, since it all depends on how many guaranteed residence students change their mind, as well as how many spots are available which isn't known.
I would always have a backup plan. Start looking at off-campus housing options.. there are a LOT of great student houses out there near campus, and a lot of first-year students looking for housemates to move in with right now
Browse the MacInsiders student housing marketplace to see:
http://www.macinsiders.com/forumdisplay.php?f=19 6