This is the 10 man version of the Shaman tier 7. There are three sets, one for enhance, one for elemental, and one for resto. The pieces were bought with tokens that dropped off various bosses in Naxxramas & Obsidian Sanctum (see below).
Tokens for the Chest and the Gloves can be purchased with Justice Points (550JP for chest & 348JP for gloves). They can be purchased in Dalaran from Arcanist Ivrenne (Alliance) or Magistrix Lambriesse (Horde).
All of the tokens drop from the following bosses:
Pieces can also drop from Archavon the Stone Watcher