Hey everybody, here's my personal take on arms and what I've found to be successful in PvP so far...
First of all, what I've noticed is that arms is FUN again. There are a few issues, but in general I think we are in a rock solid place after this patch.
Some tips, if you have to face off against a rogue, keep a rend up at all times on secondary targets. This way you can hammer him with Taste for Blood overpowers even if you can't get the rend on him due to evasion or dodges.
Write a focus overpower macro. Taste for Blood is not limited to the target you have the rend on, so make sure you can use it on your focus target to apply Unrelenting Assault.
I use
/cast battle stance
/cast [target=focus] overpower
A great time to use this is say when a Paladin has Divine Plea up.
Consider:
If you have a mortal strike on your main target, the paladin has divine plea up and you hit him with a UA he is healing for only 12.5 % of his heal efficiency. It might as well be nothing, and it lasts allot longer than a pummel. This is an ideal time for a bladestorm. Blow recklessness then Bladestorm and the damage is literally unhealable.
One of the great things I've noticed about arms this patch is the pure disruption you can produce. I've seen allot of debate (and whining) since the patch dropped about shield bash vs pummel vs unrelenting assault vs spell reflect. My solution??? Use them all. Look at the sheer volume of tools you have to use here! Be ready to use any of these for every possible situation on short notice. Have them all hot-keyed, macrod and ready to go. Note: pay attention to the order that you use them. If someone is casting from a distance, start with a spell reflection. Spell reflection is FAST. I can beat any Druid cyclone or any mage polymorph with it. But once you have that shield out to reflect why stop there? One thing that is rarely mentioned in this debate is that Blizzard DID add an instant interrupt to the arms tree on a twelve second cooldown in the form of Juggernaut (if you glyph Rapid Charging). Hit the next cast with a Juggernaut charge and the one after that with a shield bash. Then since your in arms stance anyways hit the cast after that with an overpower for a UA debuff. Or hit it with pummel, into an intercept. Blizzard has given us some amazing options here and I personally feel almost bad for Frost and Blood Death Knights with there one stupid mind freeze that is easily juked, even though they have no stance requirements on it.
A great move is to hit a healer with a focus intercept/pummel/overpower then get back on your target with a Charge. Have focus modifiers written into both your charge and intercept macros.
I use
/cast [modifier: ctrl, target=focus] charge; charge
/cast [modifier: ctrl, target=focus] intercept; intercept
Another useful macro I've found for shattering throw is
/cast battle stance
/cast [modifier:ctrl, target=focus] shattering throw; shattering throw
I hope some of this is useful to you guys, and have fun hunting all the scrub DKs and Rets who are about to get their comeuppance from the mighty arms warriors! Reply in this thread if you have any questions or any useful tips macros you've found.
P.S. As a side note; I went with mace spec and am finding it quite good. I am running Deadly Gladiator Bonegrinder and I was able to out-dps a fellow arms warrior who ran with a Betrayer of Humanity in BGs. It seems to hit DKs and Paladins really really hard. For glyphs I'm running Rending, Rapid Charge and Imp. Hamstring.
Edit: Since making this post I've changed my mind on the best pvp build as a result of discussions within this thread. Here is my modified build which I predict will become the cookie cutter arms pvp spec for 3.1. Special thanks to Cyrant for first bringing it to my attention.
http://www.wowhead.com/?talent#LcrubfIt0frRzGuioGx0o