Issue appears to have been fixed in 14w26c **
Unless it was a temporary glitch or a bad spawn place, the new Endermite does not take any damage (I was using a stone sword when attacking), or fall from gravity.
The endermite was also not making any sounds (Idle).
I was also not taking any damage from it.
Further information: (Or attached gif, same thing)
http://gyazo.com/7e2c620e723dd1697f6eb74e5c8cc949.gif
Edit: Spawned one using an Egg in 14w26c, seems to be working perfectly. Not sure if it is caused by the Enderman spawning it.
Edit 2: Spawned a bunch of Enderman, they are now spawning them normally in 14w26c. No problems.
Dupe of MC-51152