Will the Sprint Iphone 5 ever get 4G, and if so, will I get it for free?

I just ordered my Iphone 5 from Sprint and I'm expecting it to come in the mail here in a few days. One of my co workers was telling me that when Sprint gets 4G, my Iphone will have it and I will not be charged anything. Is this true?

IPhone has 4G

Yes it will have 4g for free once it is deployed in your area