Official article here.
Tournament Rules 2.1.1 here.
FAQ 2.1 here.
Not a whole lot of new stuff, mostly just getting stuff in print that we already knew about.
Biggest change of note may be that player side is now determined randomly in championship play (double-elimination) when two players have the same differential. Prior to this update, the decision was left up to a player and the player who got to choose was determined randomly.