This is 100% BiS with gear that is currently available to players:
http://chardev.org/?profile=304145 When traveling across midfield or you are kiting/running from people, You will always want to use Green Whelp Armor(Chest) with +150 HP Enchantment. When you do not have 4+ Flag Debuff, use Revelosh Boots of Stamina(13 Stam) with +12 Stam Enchantment. When your PvP Trinket is on cooldown, you will want to use Heart of Noxxion. Nature Resistance is incredibly valuable in the 39 bracket with the mass amount of rogues. Resisting a Wound/Crippling poison, especially wound poison after the buff, is game breaking for a Prot Warrior. Tauren is the best racial do to the hp buff, nature resistance, and the AoE Stun. Also, being hit cap is very important. You cannot afford to miss a Heroic Throw(Silence), Stun, Thunderclap, or a Rend on rogues in case they try to Ambush/Eviscerate/Vanish/Ambush/Eviscerate you. And thats just rogues. Boomkins are deadly in the right hands, and not to mention a hunter's DoT. There's a laundry list of reasons to stack Nature Resist. Oh lets not forget The Green tower's Proc. With Heart of Noxx trinket, racial resist, cloak enchantment, and shield proc; that'll put ur nature resist at 111. If you get hit by a crippling poison with that then I'll be damned. EDIT: A prot warrior @lvl 39 shouldnt be stacking stamina. Prot Paladins can pull it off due to majority of the max stam items give int/SP which is something that is equally valuable as Armor/Avoidance is to Warriors. Warriors should focus less on getting max stam and more on getting Hitcapped, Avoidance, and Armor; Not to mention Nature Resistance. Warriors dont have cleanse like paladins do, paladins can spam cleanse to remove poisons while warriors are useless to remove it. Since they cannot remove it, they must prevent it. EDIT2: When AGM is on CD will want to use Heart of Noxxion Trinket. So make sure you have two Heart of Noxxion Trinkets.