OS: Windows 8 (ver 6.2, arch amd64)
Java: 1.7.0_51 (by Oracle Corporation)
Launcher: Minecraft Launcher 1.3.9 (bootstrap 5)
Minecraft: 14w06a (updated Thu Feb 06 15:30:17 CET 2014)
I was just playing around with the new slime AI and started killing them in gamemode survival. The game crashed after I killed one. Tried it twice and it happened twice.