According to the Herald:
One such opportunity has gone to the former McLeod's Daughters "hunk" Aaron Jeffrey, who has already gone through one screen test to play Jackman's brother in the film. Jackman and Jeffrey - similarly tall, dark and handsome - have had regular catch-ups on Bondi, where Jeffrey is regularly spotted with his girlfriend, another actor with considerable success in Hollywood, Peta Wilson.
The official word from Seed Productions is that not all the casting has been finalised and the company declined to shed any light on Jeffrey's situation specifically. However, if he lands the role, it could propel his career into the Hollywood major league.
X-Men Origins: Wolverine is set to open in May, 2009.