I don't see a good US F1 race in the near future (if not at Indy):
Indy has had good crowds, over 200,000 this year. Strange F1 complained about Indy's banking, as its like 10 degrees max IIRC.
New York, Boston, Long Beach - I don't think we'd see another true road course with the new Spanish venue coming up.
Laguna, Road Atlanta, Limerock, Watkins Glen, Sonoma - Could be good, but none have the infrastructure needed to make it a good event. (Indy dumped like 15+ million into renovations for F1)
Las Vegas Baby - Gag me if we host another "parking lot" GP...
Daytona - Would be awesome, but of course it won't happen.