I've been hearing some mixed messages on this one from different people so I figured I'd just ask it here to clear it up once and for all:
1. Is H Maw of the Dragonlord actually BiS for resto shaman in PvP?
2. If so, why is it BiS for resto shaman only and not for any of the other healing classes?
Unless it's bugged, absolutely not. From what I remember of this weapon from retail, it gets better with more targets to heal, 10 yards in front of you and it procs more with aoe spells. I wouldn't even use it in most fights in 10m. Also, it doesn't heal the caster so its utility goes down considerably in PvP. It is at its strongest in 25m raids in fights where people stack up a lot.
Maw of the Dragonlord is only really decent on rDruids, hPriests, and debatebly hPals. You're much better off with T2 Cata weap on an rSham, and no, you don't need 2200 to wear the item.
If u plan to rating up then dont go for it get dag as ress matters alot at high mmr,in some other cases its good within bgs.other things shina mentioned.