This is a team that's given my Priest partner and I some trouble, and the only way we've been able to deal with this comp is for me to open up on the Warrior with the Priest dispelling all HOTS from the Warrior, and then using as many CCs as possible. I was reading up on the druid/warrior comps this morning, and definitely found some useful information here:
Druid/Warrior vs Priest/Rogue - Arena Junkies just find your comp on the list and see if that'll grant you any insight.

If nothing else, it's interesting to find out exactly what other teams will be looking for.

ArP until you are capped. Use Wound Poison and Crippling Poison.

As for level 19 rogues, they should die within 1 Ambush if you are using Bind on Account weapons. (Balanced Heartseeker x2 or a Sharpened Scarlet Kris) If not, your melee attacks will finish them off. The only exception to this is other rogues, or twinked hunters.

For elemental/rogue you should use ARP, but going for ARP means that Cheat Death is esentially useless, means you should not go for Cheat Death + Battlemaster. If you want to play less of the all-in AP/Resilience is probably the better choice.

How the hell is there nothing happening in this thread? Let's start talking about PvP post-4.0.1.

Lately, I've been loving my return to Subtlety sans daggers. 2/2/32 provides all the versatility of the Shadowstep Hemo build of the good old days. Being able to Ambush with a main hand sword has given me access to Waylay for an early snare, freeing my offhand weapon for another damaging poison (I use Crippling Poison on my thrown weapon and FoK to snare a group or kiting target beyond melee range). A Premed. Ambush on my target grants 5 CP, which immediately becomes an Eviscerate for a ton of damage (I've reforged a lot of my Crit for Mastery, use the Glyph of Eviscerate, and have 2/3 Coup de Grace), and from there at least half the work is done. Against most classes, I just finish with a couple Hemo hits and another Eviscerate, or perhaps a Kidney Shot if needed. Against plate classes, sometimes it takes a bit more, but not much. And I still have Shadow Dance to pop on a stubborn target nearing death for some quick burst damage.

Currently i seem to be having the most trouble with plate classes. Mostly warriors (good ones) and paladins. tips on defeating? discuss.

I'm seeing a few things with those 2 match ups.

A. Unless you pack a lunch, don't bother with Prot warriors. It takes forever to kill them, and I'm finding you just don't have the time before another toon wanders in. The best success I'm having is when I use a Free Action potion, Ruputre, and use Expose if possible. Non-Prot warriors, my previous tactics seem to still be effective.

B. I haven't got this one figured out yet. WoG is just to powerful, and as far as I can tell you just can't stop them from using it.

One thing, is it just me, or is Wound poison seriously under powered? I have yet to see any real benefit. Upper end heals just seem to ignore it. It doesn't seem to be anywhere near enough debuff to allow you to get ahead. Even against a Warriors personal heal. The damage on it is OK (it seems so), the effect is of dubious advantage.

Have you tried making an Assassination PVP spec? Envenom and poisons melt right through plate armor. At least this was the case pre-4.0, and I doubt that has changed too much. Subtlety has always been more of a clothie killer, and Envenom for plate. The only problem is we can no longer get Preparation as Mut, so choose your cooldowns wisely. In a 1v1 scenario, Blackjack could be promising, as CS will be used much less these days, so that 70% damage reduction for 8 seconds would be pretty helpful. Of course in a 3v3 match, Blackjack would be almost pointless in most cases, as your Sap target will normally be cc'd again as soon as your Sap wears off.
Also, I agree with the last post as far as Prot Warriors go. Just leave them alone unless you have a couple days to spare.