I have been MM for most of the time since BC was released. I believe I took it as far as could from a PvE standpoint. So I've recently switched to SV for better benefits to the raid. From this standpoint I really believe that the top dps spec for mm is
19/42/0 with a 1:1.5 shot rotation. It doesn't have IAotH because moving to a 1:1 rotation for quick shots is a loss of dps. If you could maintain a 1:1.5 with quick shots it should outperform the spec above but I suspect there might be some shot clipping. I have yet to try and model it on Cheeky's spreadsheet. I personally ran with 18/43/0 just because Silence shot annoys so many casters.
Of course the key to maintaining dps with MM is consumables. Mageblood, Mana Oil, BoWisdom, AoV, and Super mana pots every cooldown. But this tends to get really expensive espcially on progression attempts. Also with this spec you'll want to take as much care of your pet as a Full BM hunter as it's a significant dps loss when your pet dies.