Dishonored
 

Looks promising, most stuff from Bethesda is pretty good.

I saw this earlier, it looks SO good, and since it's from Bethesda I'm like 500x more excited for it.

edit - the game isn't being devloped by Bethesda, only published, Arkane Studios is developing it. The games they have made are:

Arx Fatalis (2002)
Dark Messiah of Might and Magic (2006)
The Crossing (TBA)
BioShock 2 (2010) - design assistance

Dark Messiah wasn't a very good game, I don't know what arx fatalis is and BioShock 2 is considered a lot worse than the original. So... we will see.

Surprise of 2012 if it comes out in 2012 looks very very promising.