Xbox 360 gamers will also be able to experience the demo with Kinect if they happen to have the peripheral, and BioWare has posted up a demo video showcasing Kinect in action which you can view here or below.
I'm still not sold on Kinect and voice commands, as I've unanimously heard that the integration was horrible in Halo: Combat Evolved Anniversary. And no, I wouldn't buy Kinect just to play Mass Effect 3 even if it did work fine.
Thankfully Kinect isn't required for Xbox 360 gamers, and it'll be great to see how Mass Effect 3 handles. Note that you will not be able to import any of your previous Commander Shepards into the demo and no game data, Single or Multiplayer, will carry over from the demo to the retail game, so this really is just a sampling of what's to come a few weeks later.
You can check out a full Q&A regarding the Mass Effect 3 demo here, and the official announcement on the BioWare Blog here.