Piracy is a big problem and it hits indies especially hard (Seriously, copying a game that costs as much as a Pizza is just fucked up).
I think the safest way at the moment would be to target locked platforms like PSN, WiiWare, XBLA, AppStore, etc. - set a lower price point and make your bet on many, many people buying it if it's actually any good.
Releasing the game just like that without any protection if you've worked for months on it is not a very smart idea. If people can copy it easily, they will. If they can't, they won't. DRM is a lot of shit, really and it's definitely not the answer - but if you invest a lot into making sure that your creation is great, it's natural that you want people not to steal it.