Strengths & Weaknesses
There are two basic PvP builds – deep Beast Mastery, which are very common pre-60, and rely mostly on their pet to do damage, and ordinary ranged hunters, who spec for Scatter Shot and then whatever else they want. Scatter Shot is the vital talent for PvP – it allows the hunter to get out of the dead zone, and is a ranged ability without a minimum range, unlike all the other shots/stings.

BM Hunters
As previously mentioned, Beast Mastery or BM hunters rely heavily on pet damage to kill, and are rather common below lvl 60. This is because the BM talent tree is excellent for levelling, so most hunters take it to get to 60 and then spec in their endgame talent spec. At 60, pet damage suffers from not scaling (which is changing in the future), and thus it becomes less effective.
The main talent in the BM tree is Beastial Wrath, which is a borderline overpowered spell available every 2 minutes, which makes the hunter’s pet a killing machine for 18 seconds. During that time, very few crowd control spells will affect the pet, most notably Death Coil. It is especially effective on cloth classes, because they have such low armour and generally know way to keep the pet off them.
The main way to get around this is to heal through it – which can be very difficult for classes who can heal. It helps if you have a partner, although often that is not the case. If you can use the terrain to escape, that will give you an excellent chance at victory. For example, if you are on the second level of the flag room in WSG, jump down, and the pet will be forced to take the long way around, by which time Beastial Wrath will likely have expired. Once the 18 seconds is up, you have a much greater chance of ignoring the pet and killing the hunter.
One thing to note about BM hunters is that they will not have Scatter Shot, so it is much easier to exploit their dead zone. If you catch them with their Beastial Wrath on cooldown, or their pet is attacking someone else, you can effectively exploit the dead zone to prevent them from damaging you from range.
Scatter Shot Hunters
Scatter Shot builds are much more common at level 60, as they are simply more adaptable and scale much better with high-quality gear. There are also many ranged damage boosting talents available when taking Scatter Shot, either in Marksmanship or Survival.

With its 30 second cooldown, it should be up whenever you get jumped in a battle, or when you decide to start a fight. It can also be used to interrupt casting, which can be particularly annoying for a healer casting a long heal or a mage channeling a big damage spell. While the duration of the mez effect (Confusion, which essentially makes the player run around uncontrollably) is only short, at 4 seconds, it is long enough for a hunter to get into range once again, and lay down a trap or simply cast another damaging spell.
It is important to remember that Scatter Shot’s confuse effect is broken by damage, so any DoT’s (Serpent Sting) or pet damage will break the effect, which can be very annoying. It is common to have a macro which dismisses the hunter’s pet when Scatter Shot is cast, preventing the pet breaking the confuse early. Additionally, if Serpent Sting is on the target, switch to Scorpid or Viper Sting before casting Scatter Shot – that way it won’t break on you before you want it to.
General Strategies
Feign Death
Feign Death is currently absolutely essential to PvP (although this is slated to change with the expansion) – not because it “tricks” players into thinking you are dead, but because it allows you to drop combat, which will let you lay another trap, which is an essential part of kiting.
Feign Death also makes anyone who has targeted you lose their target, which can sometimes help in big group situations where you have a lot of players targeting you, or when facing a rogue, as they will lose their combo points if they do not re-target you.
There is a simple macro that makes the use of Feign Death + Freeze Trap very easy – simply bring up the macro menu and input this:
/cast Freezing Trap
/script PetWait(); PetPassiveMode();
/cast Feign Death

You can use this both in and out of combat. Out of combat, it will just place the Freezing Trap, so you can replace trap icon on your combat bar with the macro. In combat, you will need to spam click the macro, and it will drop you from combat with Feign, and when the global cooldown has finished, you will jump up and place a Freezing Trap. It will also stop your pet from attacking, which helps you stay out of combat long enough to place the trap.
If you have Scatter Shot, you can make a similar macro which includes Scatter Shot, or you can replace prevent your pet from attacking when you cast it, which will break the confuse effect.
As for pets, the most effective pet for PvP is usually the fastest attacking one you can find, with Dash/Dive. Fast attacking pets are great for interrupting the spell casting on casters, and with Dash, they can quickly reach where you send them. If you can’t reach that priest that is healing the flag runner, send your pet at him, and at least slow down his attack speed (and possibly get him to blow a fear), which can help.
Macros
Scattershot for Rogues
This comes in handy when a rogue is around but you can’t see him. Bind a key to this macro and spam it when you know a rogue is around (but no one else is); it will cast Scattershot as soon as he appears, and then cast Hunter’s Mark. You will need to keep pressing the key.
/script TargetNearestEnemy(); if (UnitClass("target")=="rogue") then CastSpellByName("Scatter Shot"); CastSpellByName("Hunter's Mark (Rank 4)");end
Arenas
Marksmanship is still the king of PvP, because of the new 41 point talent – Silencing Shot. This is a silence effect, and is particularly powerful against healers. Scatter Shot is also a limited form of CC. Importantly, Marksmanship hunters have the best damage potential, and can still use traps and other hunter tricks.

BM hunters can be use to harass healers, and if they spend 41 points in that tree can be immune to virtually all CC. However, they won’t have the damage potential of Marksman hunters and will lack Scattershot.

Survival hunters have potential in smaller arenas, where there may not be dispellers. Wyvern Sting is 12 seconds, but is easily dispelled, as are traps. They don’t have the damage potential to be good 5v5 players, and don’t have the utility to make up for that lack of damage.