Blizzard has posted Patch 10.1.5 PTR development notes which includes class talent changes, changes to mana economy and hybrid healing.
The PTR has been updated with the following:NEW MEGA-DUNGEON: DAWN OF THE INFINITEThe Bronze Temple has lain dormant for millennia, awaiting a time when its dragonflight would return. But just as the bronze dragons have reclaimed their sacred temple, dark forces now threaten to overtake it.