The next accessible BG is Alterac Valley

　　The next accessible BG is Alterac Valley. AV becomes open at level 45, so that by mid way through these levels you can run up to WOW Gold four battlegrounds, making leveling through PvP a lot less monotonous. The positive aspects of leveling through PvP include getting access to honor points, which can be used to buy gear. The PvP gear accessible for you at level 60 through PvP is the original sets from vanilla, available from legacy weapon and armor quartermasters in both Stormwind and Orgrimmar. Stone Guard Zarg handles weapons and First Sergeant Hola'mahi sells legacy armor in Orgrimmar, while Lieutenant Jackspring sells weapons and Sergeant Major Clate sells armor in Stormwind.
　　The gear accessible (epic weapons like this one and epic armor like this set) will not be usable by you for transmogrification purposes (that requires that you have earned the old PvP rank that was necessary to buy them under the old system, which will not be possible for you until 5.2 opens up the system to Rated Battlegrounds, and even then you'll need to be max level to feasibly achieve it) but it's solid epic gear that doesn't have any resilience on it, meaning that running some battlegrounds from 31 to 60 will see you kitted out in gear that can easily last you until you can travel to Northrend. If you don't have heirlooms, it's definitely worth your time.
　　Talents, abilities, and specializations
　　Levels 31 to 40 see us gaining some classic and definitive warrior abilities like Deep Wounds at level 32, Berserker Stance at level 34, and Hamstring (a PvP staple) at level 36. Honestly, without the snare of Hamstring, I have a terrible time trying to PvP on a warrior. At level 38, protection warriors get Last Stand, a specialization ability, and fury warriors finally start to feel like fury warriors with the addition of Single-Minded Fury and Titan's Grip, allowing you to choose between dual wielding 1h or 2h weapons. Frankly, fury doesn't feel right to me anymore until I can dual wield pony sized weapons. Call me strange. One of the huge positive changes of Mists was moving both SMF and TG to baseline abilities and letting warriors have them sooner (you couldn't get them before level 68 in Cataclysm, a huge mistake in my opinion that Mists thankfully corrected) which really sets the spec up nicely.
　　If levels 31 through 40 start shaping warriors, the next levels continue the task. First off, warriors become able to equip plate at level 40. Then, at level 42, you'll gain Battle Shout, which is almost as iconic a warrior ability as Charge, and a nice extra piece of rage generation for you as you level. Level 44 adds Cleave, useful for high rage moments when you have multiple adds to kill. Level 45 is our third talent level (after 15 and 30) and the first one of this level bracket (followed by level 60) and we gain acess to one of the three talents. Disrupting Shout is an AoE interrupt, hitting everything within 10 yards with a four second lockout on the school of the spell beingterrupted. It has a 40 second cooldown. Piercing Howl is a 15 second 50% snare with a 15 yard range, and Staggering Shout roots all snared enemies within 15 yards for 5 seconds on a 40 second cooldown. I personally prefer Disrupting Shout at this level, an AoE interrupt is pretty sweet. But PH has the benefit of no cooldown, so if you need a snare, it's a nice one to have.