Looks to me like a brute version of the br/dmr/needle rifle/carbine. It would make sense since they haven't had one. They used the carbine but it was more Sangheili like in its design, and i think it would make sense for the brutes to have their own mid/long range wepon.
I hope this isn't true. If it is another DMR variant I won't buy the game. I'm damn sick of brutes and want the flood and bomb ass elites back.
Also, you might want to try adding voice, a more recognizable song, or making the font easier to read at some points. The halo font is nice, but it seems a bit overdone. I'm also not sure why it runs ~1:38 when your idea only goes for 40s, maybe shorten it. Great points though.
The fact that they put the human sniper rifle next to it makes me think it may be a new version of the beam rifle. It doesn't look like an assault rifle at all. The only other option would be an updated brute shot or something similar.
@Deuce, here is the plan: your loadout should be AR, boltshot, camo and sticky grenades. You should croutch around corners with camo activated and purposely miss the kill.
@Deuce, hunt the guys on sprees. When they kill you they'll think they're god and then bless you with their, erm yeah you can finish that. Either that or just completely destroy them so that when they do kill you, they will be overjoyed.