How to download Skyrim beta patch 1.5 on Steam:
Log into Steam
Click on Steam in the upper menu
Select Settings
Under the Account tab, go to the Beta Participation section and select Change.
A drop down menu will appear. Select Skyrim Beta.
Select OK.
Steam will now restart. After Steam restarts, Skyrim will be updated to the Beta version currently available.

NEW FEATURES
 New cinematic kill cameras for projectile weapons and spells
 New kill moves and animations for melee weapons
 Shadows on grass available (PC)
 Smithing skill increases now factor in the created item’s value
 Improved visual transition when going underwater
 Improved distance LOD transition for snowy landscapes

BUG FIXES
 General crash fixes and memory optimizations
 Fixed issue with Deflect Arrows perk not calculating properly
 In “A Cornered Rat,” the death of certain NPCs no longer blocks progression
 Fixed issue where Farkas would not give Companion’s quests properly
 Fixed crash when loading saves that rely on data that is no longer being loaded
 Followers sneak properly when player is sneaking
 Fixed issue with weapon racks not working properly in Proudspire Manor
 Arrows and other projectiles that were stuck in objects in the world now clean up properly
 Fixed issue where “Rescue Mission” was preventing “Taking Care of Business” from starting properly
 Fixed issue where certain NPCs would fail to become Thieves Guild fences
 Fixed issue in “Diplomatic Immunity” where killing all the guards in the Thalmor Embassy before starting the quest would break progress
 In “Hard Answers,” picking up the dwarven museum key after completing the quest, no longer restarts the quest
 Killing Viola before or after “Blood on the Ice” no longer blocks progression
 Fixed issue where Calixto would fail to die properly in “Blood on the Ice”
 In “Waking Nightmare” fixed occasional issue where Erandur would stop pathing properly
 Fixed issue where letters and notes with random encounters would appear blank
 Fixed rare issue where dialogue and shouts would improperly play
 Lydia will now offer marriage option after player purchases Breezehome in Whiterun
 Fixed issue where if player manually mined ore in Cidhna Mine, jail time would not be served
 Fixed rare issue with skills not increasing properly
 Fixed issue where the Headsman’s Axe did not gain proper buff from Barbarian perk
 In “A Night to Remember” it is no longer possible to kill Ysolda, Ennis or Senna before starting the quest
 Fixed issue with the ebony dagger having a weapon speed that was too slow
 Fixed issue with “The Wolf Queen Awakened” where backing out of a conversation with Styrr too soon would block progress
 The third level of the Limbsplitter perk now properly improves all battle axes
 Fixed a rare issue where Sanguine Rose would not work properly
 In “Tending the Flames” King Olaf’s Verse will no longer disappear from explosions