Flame thrower for a exotic would be dope (Datto said this back in D1 I think). Otherwise the only new type or hybrid type of weapons I can think of would be special ammo versions of the primarys we dont have yet like Eriana's/Choir, specially ammo rockets if you dont wanna count mountain top’s frame as one, a primary ammo melee weapon, and more primary ammo special weapons. Otherwise I cant really think of anything fully new just stuff that adds what we already have into different ammo types.