have u EVER tried killing a resto shaman with healing gear?
get a healing gear (good stuff) turn to resto, go BGs or arena when u reach 70, u will be the tank of the grp ^^
shamans are nice, but personally i prefer priests, can turn into balanced healing class, dispeller and live longer through disc, or simply really nice dmg with silence and a bit of healing if used right, the priest can be annoying if u cant control it right, but can be really nice (i mean a priest with PvP set if u are talking about pvp, iv seen priests with 12k hp, try killing them -_-)
up tell now, best for pvp, i think is gonna be the rogue, u attack from behind and the other player is dead before landing one hit on u, the rogue is the most imbalanced class in pvp, dont go against a rogue and a druid in arena 2 vs 2 ever