Mist of Pandaria is around the corner and it is good to know some key dates:(https://www.infinite-guild.eu/upload/smfpics/mists-of-pandaria.jpg)
September 25: MoP launches
October 2: Mogu'shan Vaults (normal) opens
October 7: Mogu'shan Vaults (LFR) opens, those who cleared normal Vaults can access heroic mode
October 30: Heart of Fear and Terrace of Endless Spring (normal) open, with Terrace only accessible by clearing Heart
November 6: Heart of Fear and Terrace of Endless Spring (LFR) open; queuing for Terrace requires clearing Heart. Those who cleared normal Heart can access heroic Heart, same for Terrace.