Metal Gear Rising is an action game featuring Raiden. People have referred to it as 'Ninja Raiden', like 'Ninja Gaiden'. The main gameplay gimmick seems to be 'cut anything', and the way that's executed is really similar to how the Afro Samurai game did it. They showed it off by having Raiden cut people (naturally), but also the environment and vehicles and stuff. They ended the gameplay clip by showing Raiden very carefully slicing up a watermelon.
MS's conference was pretty strong, even if nothing really got me super excited. There were no 'shoulder taps' at the end from Japanese developers, but they did say that the new 360 is shipping to retail tomorrow. Bigger built-in drive (still removeable), built-in wi-fi, smaller, shiny. Same price.
They're also mailing the new 360 to everyone who was in the audience. It's like they hired Oprah for their PR.