In MoP hunters won't be able to use melee weapons . This makes our ranged weapons even more important. In this post I've gathered all the ranged weapons that will drop from the Dungeons and Raids in MoP.
-Yan-Zhu's Pressure Valve!
-Houndmaster's Compound Crossbow!
-Firebelcher Hand Cannon!
-Taoren, the Soul Burner!
-Fang Kung, Spark of Titans!
As you can see the damage is massive as well as the stats.For now I don't know anything about the drop rates. With my night elf hunter I use only bows ,but as you can see for now the guns are going to dominate. I think that they will add a crossbow in the raid drop.
I hope the post was useful. Soon I will give you more information about hunting in Mists of Pandaria.