On Tuesday, August 27, the 13th Arena and Rated Battleground Season is scheduled to end. On that day we'll begin an approximately one week process to determine end-of-season reward eligibility.
We can expect patch 5.4 to drop around the same time.
With two weeks to go, make sure you up to date with Wrathion's legendary quest line so that you can be in a position to grab a legendary cloak. Check out Wowhead's Guide for details.