His iMDB listing doesn't have anything other than wrestling. iMDB isn't always to be trusted, but they have a pretty indepth listing of the people in Underworld, including werewolves. I never knew 0'Haire was a professional boxer *and* professional photographer, though.
You know, I noticed this as well. I went and checked out the online trailer, and I think one of the main characters looks a bit like O'Haire (he's the guy in the coffin in the trailer... which doesn't make sense since the guy in the shot phil and I are talking about is clearly a werewolf).
I don't know, that last segment worked for me. After seeing Mark Henry run around killing people for the last couple months, seeing the Big Show make him look vulnerable really built him up as a serious contender.