Following in the foot steps of the Soul Calibur series, the newest Mortal Kombat game will feature the 3rd party character Kratos from the God of War games. He's fit with his own move sets and fatalities, and comes with a God of War themed stage. He's been announced as PS3 exclusive and it's unknown yet if Xbox will have it's own unique character.
You can watch the trailer here
As for the game itself, it takes place after Mortal Kombat Armageddon and during the time period of the first three games, although with a different scenario. It will feature 3D graphics but play on a 2D plane. It's rated M and be available on the PS3 and Xbox360 with PC as a possibility.
Mortal Kombat plans to hit stores April 2011.