Are Shaman good at PvP?

Short answer - Yes.

Long answer - Each player is ultimately responsible for how ‘good’ his or her class will be in a PvP environment. As most Shaman realize, we have some rather obvious deficets in a PvP aspect in respect to other classes, however it is not uncommon for many Shaman to succeed nonetheless. Remember that we are a group oriented class and will almost always do better in a group PvP setting rather than one on one encounters.