While people have occasionally reported success getting a specific room, in general, asking for a specific room is a great way to make sure you don't get what you really want.
Requests are ordered by length of reservation, so those that reserve 11 months in advance are at the front of the list (this is one reason why it's very difficult for people that don't own at BWV to get a boardwalk view, since they only have the 7 month window). Within that ordering, medical requests come next and then smoking/non-smoking preferences.
If you still want to request a specific room, be all means do so, but also request other things that are important to you.
I've seen no advantage to faxing the "room controller" a week before arrival - the best bet is to make the request when you make the reservation.