Local Shank dev Klei Entertainment has announced what looks like a proper stealth side-scroller called Mark of the Ninja. From what little there is to see, it has the feel of a 2D Tenchu, or what old-school Ninja Gaiden would have been like if you actually, you know, acted like a ninja: sneak, avoid, distract, strike.
You have to play a little text adventure (co-written by Chris Dahlen of Save the Robot/Kill Screen, which bodes interesting for the game) to earn the gameplay teaser trailer.
I'd always meant to check out the Shank games, but now I'm definitely probably grabbing this taffer. Slated for XBLA in "summer 2012".