I loaded up the latest snapshot, loaded a world.
When on the the render distance two, sometimes when breaking blocks the fog affects the trees and they look fancy but a bit more glitched.
You can see the fog inside of the leaves.
I was on fast graphics and two chunks.
If you press t or go to the menu, it sometimes fixes it but comes back shortly.
Environment
Windows 7, Java 7
Duplicate of MC-56970