Even more than 0.15.3, this patch is primarily focused on bug fixes.
Prospective fix for occasional deck editor & collection crash / slow filter response
Increased chance of getting wild cards in packs and single card rewards
Added feature to make it easier to open multiple packs in a row. Start by clicking the first pack, after which you can press or hold spacebar to continue opening packs
Fixed a crash that could sometimes occur while crafting
Fixed a bug where your turn timer could expire immediately after reconnecting
Throttle GPU usage when application is minimized or not focused (Windows only)
Adjusted idle emotes to occur less frequently (and not at all in bot games). Custom idle emotes added for most portraits
Fixed favorite card material/trim functionality
Fixed a bug where the card collection would start at the bottom instead of the top
Added a scroll bar to the card collection
Fixed a bug that prevented Xerxian Saboteur and Forgeling demise effects from working.
Reincarnation should now work properly
Fixed a bug reported as “suppressing Herald of Pestilence opposite a Serpent on a Serpent’s Den enchantment with Singing Stone in play kills the Serpent.”
Damage effects with a value of 0 (eg Extract Life cast with 0 mana or Herald of Death demise with 0 attack) no longer deal damage to minions with Fragile
Fixed a visual bug that could cause the mana bar to show incorrect mana/gem counts when casting certain cards quickly (reported as Blood Moon followed by Panic Raider in quick succession)
Added additional sound effects
The Block feature on the Social panel is NYI
Guilds are NYI
Holding down space to open packs sometimes glitches (visual only)
Dashing Ringmaster
Rush
All your minions have Rush → Other friendly minions that are created with 4 or less strength get Rush