Maybe chain-hook is a better term? Something that can be used to trip enemies? example from Vindictus/Mabinogi heroes: http://www.youtube.com/watch?v=7cTdMS_V-fg
Chain-hook is a better term. Even if Beth doesn't include it in the vanilla game, as long as they put crossbows in, it'll be an easy gadget to create with mods. Basically a rope arrow that you can shoot out of your gauntlet and either climb or swing from.
But if they do include something similar in the vanilla game, I think that would be a badass reward for finishing a Thief/Dark Brotherhood guild.