Well, I'm late to the party here on reporting on the new changes coming in October. So we will have a new core set and some new rules to contend with in addition to the new set. I'm just going to borrow from WoTC here and I'll make my own comments...
The "Legend Rule"
The "Planeswalker Uniqueness Rule"
Sideboards in Constructed Tournaments
|Game 1||Subsequent Games||Legality|