SFStL and SDC are night and day - practically two different universes. Let's try not to have a discussion right here about the aspects of both, but I'll speak quickly for most other people here and say that we really could care less about the great many other parks around that have more and larger thrill rides. SDC is all about the atmosphere - the experience as a whole. It's like the difference between CP and Disney World, but IMO, SDC knocks DW out of the park. Rides are excellent, but if they don't have the SDC charm, it's just another trip around some tracks or through the air on some mechanical contraption.
I mean, I'll go to SFStL for the thrills, but SDC is all about just relaxing and having a good time, in a somehow completely different way. I like both types of parks dearly, but if I had to chose between the two I'd pick SDC. (Btw, I have indeed been to SFStL)
Anyway, I really think we should all just put the tilt-coaster rumor to rest - anyone with any experience in the industry will tell you it's just not going to happen. Seriously, SDC will get a Vekoma boomerang before they get a tilt-coaster.
However, as we thought they might, they seem to be focusing more on traditional SDC goers this year than thrill-seekers, what with the massive new craft barn. I don't think the craft barn will be the only new thing for 08, but I think it shows us what demographic they're focusing on right now.
There must be something big coming though, a central new attraction this year, it's been hinted all season...