It's been some time since I saw LOTR, but I remember really disliking the introduction of yet another old mysterious unknown enemy. You never know where they would've gone with this (do we?), but as it stands, with only LOTR dealing with them, I dislike the idea, because it feels like the Shadows all over again.
No, we don't know where Rangers would have gone with the Hand as yet. We may find out more when the movie book comes out, hopefully this month.
Jan