The season 4 gear is all based off the gear which drops in Sunwell, a hard raid instance that was added at the end of The Burning Crusade. I liked it because if you saw someone running around in either Sunwell, or Brutal gear, you knew that they were pro :D (or how much time and effort they had put in to look that good!)
...and a nice shield for the warrior set, even if it is a little on the big side.