Greetings,
I'll keep this simple and short: WoW is about Horde vs Alliance. It's the basic principle of the entire WoW Universe. It applies to lore, to pve design and, most of all, to pvp design.
Still, when it comes to pvp, we have, today, three entirely different types of pvp:
- World pvp
- Battlegrounds (rated and non-rated)
- Arena
It makes sense that if wow is a 2 faction game, horde and alliance face off against each other in both world pvp and battlegrounds. But it makes no sense at all that this rule apply to arena.
Look at things as they are: when you're off taking names and crushing your opponent, it doesn't matter if he's an orc or a dwarf. For the sake of winning, you kill them all (or at least try to).
So, if you are set up against teams of your own faction (for that is the rule of the arena: last man standing, regardless of his/her faction color), why can't you team up with players from the opposing faction?! An human paladin can go and kill 2 other humans, but he can't team up with a goblin?
This makes no sense. Still, if you need to put in some extra coherence in this subject, allow me to suggest that "members of opposing factions can queue up as a team for Arena, as long as they're both exalted with at least one common neutral faction". So if your human is exalted with the argent crusade, as his goblin friend is also in the same position, they should both be able to queue as a team, for they both serve a common purpose.
And this is the new pvp rule i'd like to see in WoD.