Apparently there was a live stream of the Court of Oryx. Still trying to figure out all the information, but here are a few links that point to new information regarding the new content:
** MAY BE SOME IN-GAME CONTENT SPOILERS **
King’s Fall Raid will go live 9/18/15 at 10 a.m. PST
Swords are not dropped but earned via quests.
There’s an Exotic Sword called the Raze Lighter
TTK - Court of Oryx screenshots
A rune is required to summon bosses in the Court of Oryx.
You will receive a temporary debuff for 40 seconds that prevents you from using another rune after the event is completed.
Court of Oryx has a total of 3 tiers.
Tier 1 has a random boss that has a unique mechanic associated with them.
Tier 2 have you fight 2 random bosses from tier 1 at the same time and enemies are bumped up to lvl 41.
Tier 3 will supposedly have bosses that are similar to ones from raids.
In Court of Oryx, the summoner gets the most rewards. The summoner must also be active within the arena or else the event will cancel.