The patch is live but not all is perfect yet, and Blizzard’s been updating the Diablo 3 v2.0.1 Known Issues page.
Entering a multiplayer game at the same time that the leader of the party is leaving the game can cause players to become stuck at the home screen with an unresponsive Game Settings menu
Some of the item affixes that are new to 2.0.1 do not appear in the preferred stats drop-down menus in the Auction House interface
The bonus experience granted by Pools of Reflection is removed if you die while brawling
The Images summoned by a Wizard’s Mirror Image skill will lose their metallic appearance when transitioning through a portal or waypoint
Some level 60 crafting plans require level 61+ crafting reagents
There is still an experience bar in the follower UI
The Siegebreaker Assault Beast may occasionally use his other special abilities and attacks during his grab attack animation
The Blood Star attack used by Succubi variant monsters will apply its debuff even if it is dodged or blocked
Demonic Tremor variant monsters are properly using their special shield wall ability when reduced to low health
The Risen outside of New Tristram do not grant experience
The portal leading from the second Hell Rift to the Gardens of Hope 2nd Tier does not currently function
Not listed above, but currently possible is the Auction House listing of newly-found, Bind on Account legendary items. It’s unclear if this is a bug or a feature, but plenty of the new and better legendaries are already listed. Amusingly, they show the players in the game when the item was found on the “allowed to trade for 2 hours” list.