I think they hosted the World GT8 Grand Prix down at the Homestead Raceway in Florida earlier this year which is a 1:1 track, but they also have an R/C track onsite as well. It would be cool if all full scale race tracks hosted R/C events too, that would really boost the hobby to a whole new level for sure!
I'd hate to oversell Austin, the track isn't anything super fancy like what the guys have in Dallas and Houston (Porter area). It's just a bunch of boards setup in a parking lot and the driver stand is a temporary scaffolding that is setup and taken down at the end of each race day. I think the interest for R/C in Austin is probably stemmed from most of the population being techies who love to tinker which makes for a perfect segway to R/C. I will say that some of the Austin drivers are pretty darn good, maybe not as good as Marcus, but we are certainly trying to get there!
Here is a sample of what one of the Austin track layouts look like:
http://www.youtube.com/watch?v=E14m8zjugXU
Sorry for the crappy driving skills, but it was my first time running my off-road RC8Be as an on-road GT8 by an amateur (me).