Red Dead Redemption question. ?

I'm so interested in this game and am getting it as a graduation gift; however, I don't know TOO much about it yet, other than the fact the free-roam environment is huge, you can hunt, multi-targeting, etc. What I want to know is, can you choose your own path (good, evil, whatever)? In one of the trailers, there's a Native American saying "Maybe you live in a different America than we!" and I think it'd be pretty cool to join forces with them, considering I'm part Chippewa.