If you blink, you'll miss Michael Ealy. And even though I'm not the biggest fan of the franchise, I'd be remiss if I didn't give some recognition to Kevin Grevioux who's been involved with every film in the 4-film series (thus far), as a writer and/or actor. He actually created the original concept/premise and wrote the first screenplay with director Len Wiseman, which launched the franchise.
He's in the picture above - a still from the last Underworld movie, Rise Of The Lycans in '09.
This one is due for a January 2012 release.