I will be GMing Dungeon World, an indie fantasy RPG. It won boardgamegeek.com's "Golden Geek" Award for Best RPG 2012. Dungeon World combines the "old school" flavor of dungeon-crawling, D&D-style adventure with "new school" game mechanics that are fast, flexible, and emphasize narrative, character development, and collaborative storytelling. In other words, AWESOME.
I have never run it before and am DYING to give it a try!
It's going to be potluck-style, and I'm capping this thing at six (counting myself, so really five), so plan accordingly!