Patch 5.4 is already shaping up to be a big one, and today Blizzard announced some major arena changes in addition to the tie-breaking system. Aiming to improve the arena experience by making it easier for anyone to compete, arena players will no longer need an arena team (in fact, arena teams don't even appear in the UI on the PTR): in patch 5.4, queuing for an arena match will work similarly to queuing for rated battlegrounds. You'll be matched with other players queuing to fight with and against, based on your rating. Additionally, matches are no longer limited to your battlegroup: you'll be able to play with or against anyone in your region, and even be able to compete in cross-realm groups with friends on other realms. Matches themselves will stay (mostly) the same, though your conquest point cap and requirements to purchase items will be based on your personal rating.
These changes are live on the PTR now if you want to check them out for yourself. See the full text of Blizzard's announcement under the break.