This one has slipped my mind the last few days, but if you have not heard yet, there is a listing for an option in the second Horus Heresy book that mentions a Rogue Trader Militant army. Check it out below.
Please remember that we have no further information on this, although it does look like we will be seeing this in the future. It seems that in the near future the Horus Heresy series will expand outwards and even possibly reach some of the xenos armies. Only time will tell.
via an email from polynikes on Faeit 212
Have you noticed in the second heresy book that 'Rogue Trader Militant' is an army listed as an option for the Legio Cybernetica on page 265. Could be interesting!