Just to make your wiki a bit different than THGRP you could make it actual roleplaying, people making characters and then being approved by an admin or something. (If the tribute's unapproved and is not fixed within a month the page gets deleted) Oh, and face claims (if you need more info on FCs I'll give it). Just an idea. :3
And something I almost forgot: Every month or so, an admin or the founder will set up the Games where you randomly reap one tribute from an active user, where they roleplay the Games.