Bethesda has revealed a new IP being developed for PC titled Dishonored Not much is known yet but it will be a first person stealth game with emphasis on some choice on how you accomplish your objective. Kill everyone on a murderous rampage or slip in and out unseen like a shadow, lay traps to foil your enemies and  make moral decisions that affect the world you are in without needing dialogue trees to do it. Sounds a bit like the Thief series which is  good thing to sound like but the magazine cover of the latest Game Informer perhaps indicates a more Sci-Fi feel to the setting which may give it some extra legs if they ever get around to making Thief 4.

It will be developed by Arkane studios, mostly known to me because of Dark Messiah of Might & Magic, a first person fantasy combat game using the source physics engine to allow you to manipulate the environment during combat to kill enemies. I thought that game was fantastic but not everyone was a fan apparently because it never got a sequel. Anyway you can post on the new games forums here if you want to get involved in the excitement.