I think the Indy 500 will be a good bellwether for where it’s going to go. Heck, they out to get Michael Andretti and a few of the others out of retirement just to generate some interest (especially since Mario was a driving force behind this).
One problem with American open-wheel racing is the difficulty of getting good American drivers in the series. All these guys come from Brazil and other countries with their pockets full of sponsorship money, and even good American drivers can’t compete with that.