User blog comment:KATANAGOD/8th "Black Ops 2" Intel Revealed & "Black Ops 2" Retail Poster Leaked/@comment-190.148.131.107-20120430230931/@comment-4025623-20120501063441

If the appearance is representative of what it is, I can tell you it is most assuredly not an M4A1. You can tell by the part below the rear sight on the elevated carry handle. Early M16's had an area where it thins and makes a sort of oval shape just below the rear sight. M4A1's do not have this. They have a sort of radial knob thing, which from what I gather is used for adjusting the sight. This would make it probably a Commando, although images, skins and textures change through development which could end up turning it into a M4A1, but as it is now, it is either definetly not or is an inaccurately skinned one. I doubt in any case that the M4A1 will make an appearance in BO2, but who knows.

You can check out the subtle changes in the design and appearnace of the M16 series over at imfdb.org