The downloadable version is just for reference. I called SCCA HQ and tried to order a "real" one and they are taking pre-orders for now. They said they will ship the first or second week in January. I need to study up on the cam gears thing in STS.
Got my rulebook Friday 1/13/06. No big changes for STS. I couldn't care less about cam gears right now anyway. I need to stop spending money for this season. UDP, ShortRam, Harness, Chip are enough for one season.
Then you should be good to go. If you're going to be using them in Divisional or National competition ask this question at scca.com. There someone who is part of the organization should give you an official answer.