Well "Outlaw Run" sounds like fun fun fun. Other than that, well maybe some little cars to drive. The youngins out there would have a blast drivin slow cars around a closed course.
---NO, I am not trying to turn SDC into another SFSL. But the old cars at SFSL are a huge hit. --- Also SFSL did something else in '12 that was a huge success. They offered a "DINING" tab on the season pass. IE: for a said amount of $$$ a guest could add "dining" to their season pass, and that guest could eat 2 meals free, every day they was at the park. It had to be meals however. Snacks or drinks were not included.
Of course SF passes are quite a bit different with passholder pic on them, and Im not sure the "meals only" is the best answer, but SDC could develop their own version of "free dining" with the passes. It may take a few years to perfect it, but I think it would be worthwhile.