Obviously all you people who are talking out of your ass have no idea as to what you're talking about, and just merely taking points from other peoples comments to add to your pathetic arguements.

Marks. Yes, marks hunters since BC have become the "lower" spec simnply because BM has the added attack speed, the added bonus to  your health, overall pet DPS. But here's the thing. I've done every spec imaginable. Dont believe me? I've spent over 700g on respecs at 50g per. You do the math. anyways, as a marksman hunter ( 7/42/12) and (0/31/30) Ive seen an incredible amount of paperdoll DPS increase simply because of gear, gems, and enchants. You people arent taking any of these into account when you're bitching about which spec is better. Marks hunters rely on Attack power and crit chance. So, +35agi on 2H, +12ahi on boots, +15agi on gloves...+12 on cloak..Rest are +AP. Gem yourself with the correct gems, and you'll find your DPS to increase greatly. as marks with the right gems( +8 agi, +8 crit, and the orange combo gems) with the enchants, my paperdoll DPS is at 351.6((I know, I'm only in t4/t5).

In comparison to my BM build (HOMGZ the standard 41/20/0) which given the stats needed to optimise this build(RAP and +stm essentially) you'll see a significant decrease in the DPS you put out. as 41/20/0 my paperdoll DPS was around 345.4 with the right gems, and right enchants, aswell as the right weapon. PLease dont forget about your weapon. Not only does your gems and enchants have to commend your spec, but your weapon does aswell. MArks hunters want weapons with +agi, +crit, +AP like Legacy, while BM hunters could use something like Quantum blade(Heroic Black Morass) which has +31 stm, +40 crit rating, and +108 AP(note the no +agi). Also, note that in most fights your pet is going to be hit with alot of AOES. Nightbane, Prince, Aran, Gruuls...If you waste your time pulling in, and pulling out your pet, wastingf mana to heal it just to keep you at a sustained DPS level, aswell as hoping to god a healer -might- toss on a heal...your stupid. Congrats, to those who can mend revive and resend in pet without gimping your DPS substantially.

Survival hunters, they're only ever needed for expose weakness which really is only good if you can get your agi to over 800. So, SURV is not recomended for anyone pre BT/Hyjal. I say this because : EW = % of your agi.

TSA=125AP at top rank.
EW= AGI x .25(25% of your agi)
To get more then 125AP you need atleast 500 AGI.

Easy to get you say, sure. But take into account surv hunters rely heavily on crit chance to sustain high amounts of DPS.
With 660 AGI with talents as surv, I've gotten to 28% crit. Surv hunters minimum is 30% due to the low paperdoll DPS. A surv hunter with 834agi will only do 320.3DPS(paperdoll).

So, lets do the math.(Note, all of these specs and numbers are coming from the SAME hunter, and the SAME gear)

BM paperdoll DPS = 344.6(with 2% dmg increase from talents)
MM Paperdoll DPS = 351.6(with 2% dmg increase from talents)
SV Paperdoll DPS = 320.4(With 834 agi and 28% crit)

When you say "paper doll dps" are you referring to the dps it lists on your character sheet? o.O

I respecced to just try out Survival.  I didn't contradict myself in any way.  I am back to marks.  So whatever .. In the 25 man raids fully buffed as survival I was sporting over 925+ agility and my crit chance was outrageous.  PLUS, before you start bashing, maybe you should take into the account that usually more than one hunter runs a 25 man raid.  Whats the point of having ALL marks hunters?  None.  I am a team player and if you are going to check my armory and base your opinion on that after a "month or so ago post" then I will call you an idiot as well.
I still believe marks is the superior specc to go, if you have the right gear, gems, and weapon .. and deffinetly survival if you can snatch up close too 700 agi.  unbuffed. 
I will update you guys on this though.  I respecced BM to try it out for 2's, and it owns.  MY dps sucked, cause im so used to marks, but I lived longer and the 20 seconds I am unstoppable, you can pump out a lot of bullets / arrows.  So thumbs up to BM for 2's.  Thats it though.

Meh, Bm is okay in 2's. Where it really makes its mark is raid dps though. (excluding sunwell :| I hear it is not at all pet friendly). MM can come up to par if they know what they are doing and are geared correctly, but BM also gives a superior group buff to MM. However, you do have many valid points and are probably better geared than myself (the world would implode if I could break 900 agility in my gear) so I will let it be.