That was fast, it's out!
Minecraft Beta 1.5
(You will need to update your servers as well)
* Weather (rain, snow, thunder)
* Statistics
* Achievements
* Detector rail
* Booster rail
* Performance improvements
More statistics and achievements will be added over time as we develop the game. They’re only stored locally at the moment, but we’ll slowly be rolling out online storing of achievements over time.
http://mcupdate.tumblr.com/post/4746649753/minecraft-beta-1-5
I guess this means I can take my gold blocks back lol..
edit:
unofficial wiki list:
Added Weather (rain, snow, thunder)
Added Statistics and Achievements
New Items (Detector rail, Power Rail, Birch and Spruce Saplings)
Holding SHIFT+Click on something in a chest will immediately drag the selected item(s) into your inventory and vice-versa.
Birch and Pine trees now drop Birch and Pine saplings, respectively
Performance improvements
Crafting a ladder now produces 2 ladders
If a lightning hits a pig, it becomes a Zombie Pigman
Locked Chest re-added.
Sugar Cane can now be found hanging from Trees
New settings in options:
Ability to change GUI size (Small, Normal, Large, Auto)
Advanced OpenGL (For higher-end graphics cards)
Sugar Cane can now be found hanging from Trees
Bug Fixes:
Climbing a ladder with gaps will not work anymore.
On fancy graphics, the sides of grass blocks are now biome-specific and match the shade on the top.
You can now move through flowing water at previous speed.
New Bugs:
Achievements only work in SMP if you have already completed first achievement in Single Player
The Game crashes when Detector Rails are placed beside normal rails.
Skeletons can shoot through the corners of glass.
Blocks can't be placed on snow.
If you change Advanced OpenGL to on and then back again, giant holes will appear that you can see through.