Question about Upgrading or downgrading 5.1 ... !?

I have a friend who purchased a new iPhone 4S yesterday, and the iPhone came with iOS 5.1, and as I learned 5.1 does not have a jailbreak !? and upgrading to 5.1.1 or downgrading to 5.0.1 ( for example ) I think is not possible ( since I don't have any SHSH blobs cuz the mobile is brand new ) ,, so is there any workaround here !? :\