Can I do the new Vidmaster Annual achievement in halo 3 with me and my brother on

[Duderdas]

our accounts on xbl with 2 ? other players on live....will we still get the achievment

 

[chocolatecereal117]

If you mean with the ghost and iron skull then no.
Vidmaster Challenge: Annual Complete Halo on 4-player Legendary LIVE co-op, with Iron, and everyone in Ghosts.