Blizzard's Ghostcrawler put up a post inviting hunters to post their concerns about PvP.
Here are some of mine:
My hands are small and I'm running out of keys. At 70 my hunter had more spells to use than my warlock, and now with the new pet abilities (Charge/Intervene etc) the problem is worse.
2. Mana and burst damage
Mages can choose to conserve mana and do lower, constant DPS, or blow their whole mana pool and do huge burst. Hunters don't have this option - we go through mana quickly and do high DPS *all* the time (*if* we stand still), which is great for PvE but not for PvP.
3. Pet survivability
A lot of our "escape" abilities are linked to our pets. If a warlock demon dies, the lock loses maybe 1 "save" spell (eg. Silence from felpuppy), but they still have fear/deathcoil/CoEx etc. When hunters lose pets, we lose Master's Call and all the pet abilities, 3 or 4 of which could be considered "save" spells (Charge, Intervene, Roar of Sacrifice, Pet Family Special). BM hunters especially will only have Disengage and Deterrance left, which are only useful against melee and not casters (unless you take Scatter Shot).
Old issue, but they're still unreliable. If opponents are smart, they can choose to avoid it (by having someone with a DoT eat it, for instance, or just run around it). Freezing Arrow is not much improvement on Freezing Trap.