Time for a new snapshot! The major changes are:
Notes about the new texture pack system: Starting from this snapshot and forward, blocks and items will no longer load their artwork from one big sheet of sprites. Instead, they’ll have individual files for each image they’re using. The benefit from this is that it will be easier for us to support custom blocks and items in the future. It will also allow us to mix and match block artwork resolutions, and make sure that you get graphics for blocks that your current texture pack isn’t updated for.
Credits: The Minecraft Team