Via the Dota 2 website:

HEROES

BATRIDER

STICKY NAPALM

• Sticky Napalm now deals 50% less damage against all creeps.

BEASTMASTER

• Base attack speed reduced from 110 to 100

CALL OF THE WILD BOAR

• Call of the Wild Boar movement speed reduced from 350 to 320/330/340/350

EARTHSHAKER

FISSURE

• Fissure shard aftershock replication now stuns for half duration

KEEPER OF THE LIGHT

RECALL

• Recall delay increased from 3 to 5/4/3

LYCAN

SUMMON WOLVES

• Summon Wolves duration reduced from 55 to 50 seconds

MORPHLING

MORPH

• Morph cooldown rescaled from 160/100/40 to 140/100/60
• Morph scepter bonus cast range reduced from 600 to 300
• Morph scepter now also reduces Morph cooldown by 20 seconds

NATURE'S PROPHET

• Greater Treants Base Attack Time increased from 1.0 to 1.4

NYX ASSASSIN

VENDETTA

• Vendetta no longer applies Break
• Vendetta cooldown increased from 90/70/50 to 90/75/60

OUTWORLD DESTROYER

• Movement Speed reduced from 325 to 320
• Base armor reduced by 1

ARCANE ORB

• Arcane Orb cooldown increased from 4/3/2/0 to 6/4/2/0

ASTRAL IMPRISONMENT

• Astral Imprisonment manacost increased from 120 to 150

PUCK

• Base damage range reduced from 46-57 to 46-54

WANING RIFT

• Waning Rift damage reduced from 70/140/210/280 to 70/130/190/250

DREAM COIL

• Dream Coil scepter stun duration reduced from 2/3.25/4.5 to 2/3/4

RIKI

TRICKS OF THE TRADE

• Tricks of the Trade scepter no longer increases duration

TALENTS

• Level 25 Talent reduced from -6s Tricks of the Trade Cooldown to -4s

SHADOW SHAMAN

SHACKLES

• Shackles Shard cast range reduced from 150 to 125

VOID SPIRIT

• Base damage reduced by 2

WRAITH KING

WRAITHFIRE BLAST

• Wraithfire Blast cooldown increased from 14/12/10/8 to 17/14/11/8

VAMPIRIC SPIRIT

• Vampiric Spirit skeletons base damage reduced by 3

Rumor has it:

• This one also includes a sprinkling of localization file updates, made possible in part by contributions from Translators Like You – Thank You

• Size is close to 50 MB (with Workshop Tools installed)