Apologies to all you Texans out there, but is there REALLY that big of a Formula 1 fan base in your parts?
New York was always the most logical -tons of tourists as well as a large expatriate population. Also quite a decent amount of awareness of Formula 1 among the general population. LA would have been my next bet, given the car culture and diverse demographics.
I don't see hosting a race in Austin any better than having it in Indianapolis. Location is key in Formula 1 - if the track design is not a classic (and if Tillke makes it, it won't be), it's bound to follow the fate of other middle-of-nowhere tracks like Jerez, Magny-Cours, etc.
The appeal of having it in a big city is that the whole family can come along, and it provides a reason to visit other than the race. What foreign tourists will fly all the way to Austin, Texas, just to see a race on an uproven track?