This is based on what I remember, and it was nearly a year ago, so hopefully if I get something wrong/don't remember it all someone else can fill in the gaps.
There were a few hotel rooms left in Mission Valley (interestingly enough, pretty much the same ones offered during the Early Bird sale). If you booked the room through Travel Planners, you got a free 4 day badge for each occupant. Some of these badges (apparently at random) included Preview Night.
HOWEVER, last year they did NOT have the Early Bird sale. This MAY mean that they don't have enough hotel rooms left this year to make the hotel/badge sales worthwhile. I don't know.