This has probably been brought up before.
But with the focus slightly shifting back from an arena tournament organised by a single organisation, that doesnt really care about teams being alliance or horde. (hence all the gear looks the same for both factions), to the "strategic" defence or offence of alliance/horde strongholds AKA Battlegrounds.
Wouldnt it be swell again if we could get the faction based armor back? Spikes and voodoohoodoo for the horde, shiny golden eagles for the Alliance. Back like the Grand Marshal stuff.
Heck maybe even some new tabards that are faction based like the old sergeant onces, but these new tabards should give a slight bonus in pvp and pvp only, so that players would have an insentive to wear the colors of their own army.
Back in thoe old days, you could see a distinct difference between two incomming armies (sure the races are a bit of a giveaway) But in a real war situation it would be just way to confusing for both sides to wear the same uniform.