If you pre-order UFC Undisputed 3 (out January 2012), you'll get some of the planned DLC content for the title absolutely free. That content includes fighters Nick Diaz ("El Diablo"), Phil Davis, Jason Miller and Brian Stann.
UFC Undisputed 3 - John Bones Jones
UFC: Undisputed - Frank Edgar
UFC: Undisputed 3 - Cain
Supremacy MMA - Shane Del Rosario