It's a very interesting race, they actually go the opposite direction than the MotoGP (bikes) do. They tested new aero kits on the oval last Sunday, and 2 Penske cars were instantly up to 228. The GP race cars are quite a bit different though.
A general admission ticket is only $30, and that lets you go about anywhere. The mounds are a cool place to watch, you can get within 40-50 feet from the cars braking or accelerating, awesome feeling. The crowd last year was around 70k people, which seemed completely vacant. Indy gets you in and out in a hurry.
They did replace all 16 large exterior TV screens with new ones that are much larger, and have a lot better picture. The local hotels know how to treat people also, unlike some cities. The F1 race in Austin is an example of gouging the public….$8 bottles of water, hotels quadrupling their normal rates. I noticed in Austin a Hampton Inn an hour away was $600 per night! Their ticket sales will suffer from that.
There is a chance of rain Sunday, but I believe they race in the rain. If you need any help finding a place to stay, or where to stay away from, just ask. I think Indy is on of the nicest cities around, it's very clean, and they appreciate the crowds.
Also, I'm not sure if you've been there or not, but you have to at least watch a little bit of the race or practice along the front stretch on the outside. It's in the shade under a balcony, but the cars flying by over 200 mph with the engine sound reverberating under that shelter will bring goose bumps. Come back in August for the MotoGP bike race, they are louder than the cars, and faster down the straight.