The reason why most private wow servers today are 3.3.5a is because that was the last patch for Wrath of the Lich King, which is the last of the great wow expansions. The Cata and MoP expansions suck so bad that over 7,000,000 players stopped playing World of Warcraft. Many players, including myself, miss classic wow and want to play the game the way it was meant to be played.