Enchants aren't working inside instanced pvp, which are BG's and Arenas. However, enchants work fine for world pvp.
As for consumables, I haven't encountered "new" consumables. But then again, we might have different opinions/definitions of what's new and not. Consumables are great for PuGs now since every stat counts. Maxing out your ilvl only gives a tiny advantage, but stacking up on consumables actually makes the difference somewhat noticeable.
Armor bonuses, whether it's resistances, stats etc. doesn't matter at all in instanced pvp since they won't get triggered at all.