It was raining today so of course i had my wipers on, and somehow one of my wiper blades came off the rail and scratched my windshield all to hell. Is there any type of compound or anything that can take this out?

Call up your local windshield repair shop, they should offer a service where they can get rid of all your scratches and rock chips. As for doing it yourself, can't say that I know.

I had the exact same thing happen... all of the sudden my wiper blade just flew off the windshield and the medal piece when up and down once before I could turn it off. So I have a scratch that looks like a semi-circle.

your local windshield place will probably fix that for like $10