5 shaman, PvE vs PvP

Ok, am about to start up 5 tauren shaman (decided warstomp + 5% hp > axe specilization) on blackrock to join up with my old eq/eq2/wow/ao/everything else guild and am wondering what sort of changes I would need to be looking at in regards to talents, etc leveling up.

I notice on the wiki the elemental pvp spec ignores getting ToW and was wondering what the reasoning for that was, apart from perhaps needing the point to get em and ns from the resto tree. I was considering just using the PvE guide, since it matches up with the way I leveled Baanmee over the time on proudmoore, but thought I'd check given I haven't played on a PvP server since about 3 months after vanilla launch :)

I use NS on my lone shammy (not a pvp server) for instant heals... it's saved my life so many times in instances and levelling that I wouldn't replace it with the totem of wrath.

For pvp I would prefer the ability to trigger an instant cast lightning bolt/ chain lightning especially if I can use it in conjunction with elemental mastery. (an instant guaranteed crit will make most enemy think twice). I'd also prefer to have an instant big damage spell for when I'm up against a melee (especially if that melee has an interrupt ability).

I'd happily give up totem of wrath just to have that rare occassion where I pop NS and elemental mastery and it procs lightning overload :)

Now that is from a lone shammy point of view...With five shaman you will probably encounter the lightning overload situation more often.

I think it would be wonderful to get attacked by a few alliance, then have five shamans fire off instant chain lightnings with guaranteed crits.

I'm 41/0/20 on my shamans and I do both PVE+PVP+Arena.
The only place i would really notice NS is very rarely in battlegrounds and arenas i'd use it a bit.
But because I do alot of battlegrounds aswell as instances ive decided to stay with ToW. Its a good boost in battlegrounds and i find it more useful than NS.
ToW is more the hybrid spec i believe, I havnt gone NS yet, but im finding that there is no need until i take arenas more seriousally.