I got 1 moonkin and 4 elemental shammys. And using the moonkin for pvp arena dont really add me anything. The shammys have the +5 crit aura now through Elemental Oth. And apart from that i basicly just use longer time when it all goes down as i need to add the extra thingis from moonkin. Aka. Place tress. start starfall etc. Also my druid cant really heal. So you will lack some sup healing that the shammy gives from spaming up chainhealing.

So for pvp in arena i will continue using my 4 shammys. Leaving my moonkin for solo arena.

In Bgs its another story tbh.. The ability to root ppl and then nuke them down.. Like i had placed my root on the same button as the 4 shammys lightening bolts was really nice for BGs. as i would allways keep my target rooted before it was nuked down. So aoeing mages... rogues.. they would all be down in seconds that way