Warriors at range tend to be extremely squishy. Maintain max distance, lots of concussive shotting, stay out of charge range and its an ez win.
If they close the only advice I have to add to this thread is to start making a habit of standing on a freezing trap at all times in bgs/arena. Warrior charge is easily negated by sitting in the freezing trap, also you'll find that rogues/ferals are a lot less scary when they freeze themselves during an opener. If you have to rely on placing the trap after you're at a disadvantage.
Some of the initial reactions I have dealing with warriors.
Throwdown = bestial wrath out of it.
Heroic leap = scatter shot (but honestly how hard is it to zig when he zags to leap to you. It's really luck when a warrior leaps on you. (Or an indication you stopped moving for some reason, tsk tsk.)
When he whirlwinds then you disengage. Don't disengage until you see the tornado of pain. Most warriors will charge, throwdown, snare, then try to WW on you. If this happens you wrath/trinket and disengage. You've just won the encounter…
Make sure you wing clip, concussive shot every chance you get, (macro wing clip to your disengage)
Masters call = free separation, very effective if the warrior just used two GCDs to double hamstring you.
Make sure that when he's on you for those short periods after a charge you flip to fox aspect. It increases your focus regen.
Constantly recycle the use of your traps, slows, freedoms, scatters nonstop and you win. His stuns suffer DR, your CCs are all different DRs. You are more likely to win the longer the fight goes on. Don't forget to macro your spirit beast heal to something so you don't forget to pop it every chance it is up.
Trinket when you mess up anything above. Blow deterrence during his burst. Pet stun just to piss him off and create more distance. BM Hunters should win every duel against an equally skill/gear warrior, no question.