http://www.reddit.com/r/Diablo/comments/22jusd/204_undocumented_changes/New Paragon portraits (pic)
Text for monster health bars now has commas
New Gambling Item Icons
Crusader's Iron Maiden passive is now grants significantly higher thorns damage and appears to scale with Torment level
Quests you haven't completed are a different color in campaign mode
Life per Spirit Spent is less weighted on sheet healing
Moonlight Ward now has a 1-2 second internal cooldown
Pools of Reflection show as empty on the minimap when someone takes it, but still shows up as full on the full map
Removed 50% CHD cap on pets
Mirrorball was changed so that every Arcane Missile doesn't give a chance to proc things. Examples: Thunderfury proc chance, LoH, APOC.
Archon now has new graphics depending on the rune that you are using
+% Elite Damage now stacks additively
Demon hunters, 'Twin Chakrams' fire rune now goes through most world walls, like the other runes
If you get a legendary from Kadala it shows up in chat