The hunter is getting pretty jacked as of late. Made my engi goggles, got my epic ring from the ER, looking to upgrade trinkets to 346, legs, and shoulder and I'm all there and above. I leveled as MM, and have DPS'd heroics in a MM spec as well as the Surv one I'm running right now. I've heard that BM is behind in pure damage (to a point where getting BL for a non-BL group isn't even worth it) and I haven't even tried it out. BM's simple priority rotation just isn't my cup of tea.
MM does decent enough damage, and the burst potential is definately there. After you ramp up and pop racial+rapid fire, a chimera, readiness another chimera and burn through a second rapid fire I was usually around 16k. Surv can also do this, but that's happening when you are critting and procing a LnL which can possibly be RNG (If you are not trapping). Surv overall in heroics is much better as the AoE is leaps and bounds ahead, while also being higher overall damage on any boss fight, as MM comes back to earth after its 2 CD's are blown. Also, Surv get's an additional CC method (which is nice in that even in a great guild run I'm usually the only one CC'ing and I'll get both off with ease, and they are staggered in length). There is not a Heroic trash pull that isn't easier with effective use of CC of some sort, and I use my hunter utility as much as possible.
This brings me to my next point- the reason why I'm better than my other two dps counterparts in our 5man. Let's say we are all doing ~12-13k depending on the fight, CC'ing as much as we need to, and not being bad. What separates me out from them? I have MD, I have a tranq, I have a taunt, I have two slows, I've got a blind (in scatter shot) and I use them as much as possible. Scatter shot is harder to find times for, but I've been known to scatter healers who are marked as our secondary kill target so they don't get a heal off while we burn down the first target. Tranq should be used any time possible. If you can tranq it off, then you probably should be. I run most heroics with my good buddy who is a rogue and there are things I can tranq off and things he can't shiv. If he can get it easily and isn't moving around a lot- he usually does. If he's dodging fire and ground slams and such, I take over fully even though it's a larger dps loss for me. It's easy to work this out and my dps loss is made up for the fact the healer uses less mana and we move as a group faster. MD is used every fight, sometimes multiple times. No longer does transferred threat stay there forever, so I don't usually use it mid fight unless adds are running around, but every trash pull, every time. Why wouldn't you!? Slowing mobs is VERY useful. If you have a pull where you healer is going to get aggro and your tank is trying to round things up, slow them down for him! Your tank will love you as it becomes so much easier to grab everything and build threat if it isn't running, but walking.
Our taunt. You may say "Tur! Why on earth would you ever use a taunt in a group! You would kill yourself!" This may USUALLY be true, and when I'm tanking if someone starts taunting my stuff I usually get real mad- BUT if you know what you are doing you can do some SERIOUS help here.
Case 1. The tank death.
-Tank died? OH NOES!? What to do what to do! Generally our Boomkin has more threat than me (which is good) and things go running for him. If it's a big ugly I usually get as much space between the boomer and me, and when he's about to smash his face in I taunt and keep running. I throw up a slow (if he can be slowed) and dude keeps running at me for the length of the taunt. Note- while running at me he probably isn't hurting anyone, allowing your healer to catch up or take a break. When my taunt wears off he runs back to the boomkin and I taunt again when he's close. I ping pong them around until they are all dead.
Case 2. The Tank is getting low on life.
-Tank getting hit REALLY hard and has a lot of mobs on him? Taunt the biggest one if the tank has sufficient threat, let him get near and FD. This allows the tank a few precious seconds of not getting hit, and any healer will tell you that now 3-6 hits from the harder hitting melee mobs will give that tank time to get his life back up. Be careful on this one, you can die if your FD is resisted and you are too close.
Case 3. Adds.
-In a lot of fights we don't have our tank even deal with adds. We have enough dps to burn them down fast enough and the only real problem is they aggroing on the healer. Taunting them to you allows your healer to heal you instead of getting pushed back while trying to heal himself. And you are in mail as opposed to his cloth/leather/spirit plate.
On top of this, I've bought time for druid tanks to battle res, reposition mobs, and countless other useful things. Once you start using your utility buttons other than just straight dpsing, you become a more complete hunter. Also, make sure you are communicating each of these uses to your group. The worst thing ever is when you try to taunt a mob from your tank to let him take less damage and he taunts back and dies. If you talk it out, people will usually understand.
Happy hunting!