There appears to be more noticeable pathing flaws in this snapshot than previous release versions and snapshots.

Pigs/Sheep/Cows can get stuck following a player with food up 1 block rises. When this happens, the animal appears to continuously jump on the edge as if it is unable to jump up 1 full block.
Steps to reproduce: hold food and get passive MOBs to follow player. Eventually, they will get stuck jumping on the edge of a 1 block rise.

Aggressive MOBs pathing to a player sometimes stop for no apparent reason. This can sometimes appear as lag and the MOBs eventually start pathing to the player again, but sometimes when the MOB stops chasing the player, it will not go after the player again until it is affected by something (adding/mining blocks in it's path, attacking it or another social MOB.)
Steps to reproduce: Aggravate MOBs and have them follow you. Eventually some of them will stop chasing you for no reason. Some will start chasing you again, but some will ignore you even when you are 1 block away and do not start chasing you again until you attack or push them.