In the comics:
Agent Zero AKA David North was originally known as Maverick and willingly worked with Team X/Weapon X after he had to kill his own wife when he found out she was a spy. To protect his teammates, North killed his own brother. Maverick was always considered one of the best mercenaries out there, but he contracted the Legacy Virus, an illness that effects mutants and kills them slowly. He did die from it but then brought back to life and the Virus vanished. He was brought back to Weapon X to save his life, and he changed to Agent Zero with a new look. Recently he was depowered and no longer a mutant. His gifts were once to absorb kinetic energy, but he is still very deadly due to his hand to hand combat and marksmanship abilities. Honestly, he doesn't really need powers to kill you.
In the movie:
Played by Daniel Henney (his first American role), Agent North works willingly for Weapon X and plans to help track down Wolverine when he goes rogue. You can see him in the helicopter that Wolverine flies into in the trailer.
In the comics: John Wraith AKA Kestrel was a member of Team X and Weapon X like most of the characters in the film. Wraith is a teleporter and used more defensively to get the team out of bad situations. He did not like using his powers very much, and showed up a few times only regarding the Weapon X storylines. He was murdered by teammate Sabretooth for not being able to get Maverick back to Weapon X willingly.
In the movie:
Played by will.i.am
, he appears to be a teleporter in the Weapon X group. You can see him fighting Sabretooth, who also fights Wolverine so perhaps he is on Logan's side. Chances are if they follow his actual storyline, he might not survive a fight with Sabretooth.
John Wraith Trailer
Watch "X-Men Origins: Wolverine - Clip - John Wraith"
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