Arms Warrior
Rotation
Opener: Charge, Bloodrage, Battle Shout, then Mortal Strike on cooldown.
Priority: Mortal Strike > Whirlwind (when 2+ targets or MS is down) > Overpower when it procs > Heroic Strike as a rage dump above 50 rage. Keep Sunder Armor stacked if no Protection warrior is doing it.
Cooldowns: Sweeping Strikes with Whirlwind on packs; Recklessness on the boss pull or a burn phase; Death Wish before a kill window.
Forever notes: Forever: Deep Wounds still rides your crit, so Agility and crit gear matter more than in Classic; a 3.6+ speed two-hander beats a faster one with better DPS.
Stats
Hit to 9%, then Strength (attack power), then crit, then Agility. Weapon damage and speed matter more than any stat: a slow two-hander with a high top-end makes Mortal Strike and Overpower hit hardest.
Use the pre-raid dungeon two-handers until raid drops; a 3.6+ speed weapon beats a faster one with more DPS on paper.
Numbers for every spec and a gear comparer: stat weights.
Where it ranks
See the tier lists for PvE and PvP placement, and Classic vs Forever changes for what Blizzard altered in this class.
Wowhead and Icy Veins keep spec guides of their own: Icy Veins Arms Warrior, Wowhead class guides. Our rotation notes are editorial, written for the Nov 2 tuning.