The trailer doesn't need to have any kind of special "voice". The best thing, imo, would be to actually have one of the developers talk normally and explain the game's features as they're being shown in the trailer. I think that would inspire much more confidence than any kind of "acting".
The first duty of every Starfleet officer is to the truth, whether it's scientific truth or historical truth or personal truth! It is the guiding principle on which Starfleet is based! *Jean-Luc Picard*