I don't really think that this is it - as surv I was doing a lot higher dps than him with the same gear, so I think that it is, to an extent at least, something wrong.
So, lets go off the checklist. You playing surv? Black arrow staying up number 1 prio? Spamming LnL procs? ES on CD?
Do you have ANY free space in your rotation? Cus hunters should have 0, its not like playing frost dk where theres periods of standing there doing nothing. Ever GCD should be being used.
Some minor things that will increase your dps:
If you are using FS, as you are, dont use TOTH. Use Steady Focus. FS counts as 2 shots for steady focus, much better.
Curiosity - why did you get those legs? The pvp vendor also sells multistrike legs. Its irrelevent cus its not that big of a deal, just curious.
Other people are saying its the weapon - weapon damage isnt THAT big of a deal for surv so I doubt that was a huge deal.
For reference, here's my armoury:
http://eu.battle.net/wow/en/characte...taeonis/simple
I'm pulling around 32k dps on butcher, and my gear really isn't much better than yours. It HAS to be something to do with rotation. Steady focus will help a bit, but go check out that guide that's up there and make 100% sure that you are doing that rotation right, and try to get some logs if you want more precise help - we can only guess at what's going wrong.