Mark of the Ninja
the new game from klei entertainment, makers of the Shank series. Looks pretty sweet. Same sexy fluid 2d animation sported by Shank, now in a stealth platformer. With a more strategic, situational gameplay style. Maybe one of the better "Ninja" games I've seen. It's due out this summer.
The link to the main site above has their debut trailer on the front page. Here
is more comprehensive vid from pax.