Michigan is by far some of the best racing I've ever witnessed in my life, and when the IndyCar Series contacted Michigan about possibly replacing the cancelled China race this year Michigan told them that's fine, but we can't afford the sanctioning fee you're asking for a race. It's my understanding they were told the same by Road America.
In other words the people that own and control these tracks don't believe they can make a profit by ticket sales, souvenir sales, beer & food sales, etc. after paying the Indy Car Series sanctioning fee.
Maybe it's time the Indy Car Series looks at lowering their sanctioning fee, and getting back to these venues.
It is my understanding that the road course track in Portland, Oregon has contacted the Indy Car Series and said they were interested in getting back on the schedule in 2013, so instead of another oval we may get another road course.
The other rumor is the new road course they're building in Austin, TX wants to be on the 2013 schedule, so yet another road course.