The fate of the SS US depends upon the success NCLA in the Hawaiian market. The quicker NCLA can turn a profit, if it ever turns a profit, the more likely NCLA will want an additional ship. It's far more cheaper to refurbish the already stripped down SS US than it is to build an entirely new ship in America.
Never-the-less, after any refurbishment of the SS US with it reentering active service, it would be the smallest ship in the NCLA (NCL) fleet. I would hazard to guess a complete redo and modernaization of the entire ship will have to be done to make it economically to operate and maintain, as many of it's parts aren't readily available anywhere in the world.
Therefore, it isn't very likely it will reentering service soon. I still think it's more likely for NCL to refurb the SS US than the SS Norway.