I'm actually super hyped about this, but I do wonder what exactly it will be. Blood elves were one of the few races that didn't really have much in terms of recurring asthetics, besides the fact they like wearing red and gold.
I have a few ideas of what it could be. Either Spellbreaker-like armor:
Or possibly Kael'thas plate:
Personally I'd love the Spellbreaker armor.