Full Changelog:

• Secret feature
  • /stats to allow easier changing of CommandStats – via
• Chunks now use block states instead of metadata
• Servers can now customise network compression in server.properties
• Enchantments and effects now accept names instead of arbitrary IDs.
• Improved performance with rendering
• Added an option to disable (weighted) alternate block models
  • Screenshot 
  • When turned off, the least complex highest priority model will always be used for each block
• Fixed some bugs
  • Fixed z-fighting on the TNT flashing graphic
  • Fixed rain going through upside down stairs
  • Fixed text color in hopper and brewing stand UI changes
  • Fixed iron golems being able to see invisible hostile mobs
  • Fixed normal players being able to use player selectors
  • Fixed tools not breaking packed ice faster
  • Fixed mobs not being targeted by team selector
  • Fixed horses not converting their owner to UUID
  • Fixed “/weather rain” executed when weather is clear setting the weather to thunder
  • Fixed the negative color crosshair when using resource packs
  • Fixed smooth & chiseled sandstone and chiseled quartz having an incorrect bottom texture
  • Fixed double stone slabs using the wrong texture
  • Fixed servers not logging anything
  • Fixed blacksmith building generating with upside down half slabs instead of double slabs for the roof
  • Fixed pistons extending and retracting on placement as if they were powered
  • Fixed fence gates being placed open
  • Fixed redstone repeaters visually functioning invertedly
  • Fixed powered rails, detector rails and activator rails being flipped on an east/west slopes
  • Fixed the iron and wood door textures
  • Fixed command blocks placed on redstone blocks using dispensers not triggering
  • Fixed the pumpkin/melon seeds texture
  • Fixed command blocks not sending redstone updates when placed
  • Fixed desert temples generating with ignited TNT
  • Fixed heads, beds, and doors not being placable inside snow layers
  • Fixed the horse jump bar appearing even when the horse isn’t saddled yet
  • Fixed beds spawning players inside transparent blocks
  • Fixed translation strings being split up across lines
  • Fixed using cow spawn eggs on mooshrooms spawning baby mooshrooms
  • Fixed sign formatting codes leaking into the GUI
  • Fixed fire placed to the side of TNT only rendering on the side of the TNT

Mojang said:

We’re starting to enter the last phase of our development cycle for 1.8, and so we’ll be focusing on finalizing features, fixing bugs and optimizing the game over the next few weeks as we draw a little closer to something we’d like to eventually consider releasable. Todays snapshot is one such example, bringing (hopefully) some big optimizations to the server and client, a few less bugs to worry about, and a handful of hugs in their place.

Notable Changes:

• Servers can now customise network compression in server.properties
• The new block model format for resource packs can be considered stable and ready to use.
• Enchantments and effects now accept names instead of arbitrary IDs.
• Alternative (random) block models specified by resource packs can now be disabled in Video Settings.
• Many optimizations to both the server (including singleplayer) and the client.
• Less bugs!
• Compressed space and time.

Fixed Bugs:

• [Bug MC-1532] – TNT Flashing Graphic when lit looks cut up and faded. / Z-fighting
• [Bug MC-2990] – Heads, beds, and doors can’t be placed where there is thin snow
• [Bug MC-8858] – Rain goes through upside-down stairs
• [Bug MC-13633] – Horse’s jump bar appears even when the horse isn’t saddled yet
• [Bug MC-16608] – Text Color in Hopper and Brewing Stand GUI changes
• [Bug MC-18477] – Iron golems can see and attack invisible hostile mobs
• [Bug MC-23940] – If you sleep in a bed near a transparent block, you can get in the block
• [Bug MC-36718] – New fragmented sentences in translation
• [Bug MC-43984] – Normal players can use player selectors
• [Bug MC-46674] – Tools cant break Packed Ice faster
• [Bug MC-53022] – Mobs not being targeted by team selector
• [Bug MC-53166] – Horses do not convert their owner to UUID
• [Bug MC-55490] – Spawning Cows on Mooshrooms
• [Bug MC-55515] – sign.edit with §(color) changes the sign color
• [Bug MC-56251] – “/weather rain” executed when weather is clear sets the weather to thunder
• [Bug MC-56884] – Negative Color Crosshair when using resource pack
• [Bug MC-58067] – Smooth & Chiseled Sandstone & Chiseled Quartz has Incorrect Bottom Texture
• [Bug MC-60035] – Double slabs become seamless
• [Bug MC-60039] – Server logging broken
• [Bug MC-60093] – Blacksmith roof slabs oriented wrong
• [Bug MC-60126] – Pistons retract on placement as if they were powered
• [Bug MC-60150] – Fence Gates Placed Open
• [Bug MC-60151] – Redstone repeaters are inverted
• [Bug MC-60152] – Powered rail, detector rail, and activator rail are flipped when on an east/west slope
• [Bug MC-60153] – iron door and wood door
• [Bug MC-60156] – command blocks don’t trigger when dispensed onto a redstone block
• [Bug MC-60208] – Pumpkin / Melon Seeds fully grown when planted
• [Bug MC-60297] – Command blocks not redstone updating when placed
• [Bug MC-60349] – TNT spawns ignited on Desert Temples
• [Bug MC-60483] – When placing fire on side of tnt it only renders on the side
• [Bug MC-61022] – Pumpkin stem with wrong texture

Please report any and all bugs you find in Minecraft to bugs.mojang.com. If nobody reports a bug, we can’t fix it!

To get snapshots, open your launcher and press the “New Profile” button. Call it “snapshots” and check the box saying “Enable experimental development snapshots” and save. To switch to the normal version, you can select it in the dropdown at the bottom left corner of the launcher. Back up your world first or run the game on in a different folder (See the “new profile” dialog).

Snapshots can corrupt your world, please backup and/or run them in a different folder from your main worlds.