There is a very VERY major bug with the skins in this snapshot. I first noticed this when I took the block I was holding out of my hand, and the arm was blue (part of Steve's shirt). I pressed 'e,' and EVERYTHING was distorted. It was the same when I went to 3rd person view with 'F5.'
EDIT: This happens after you die in some way... Skins are perfectly normal before this happens. Also, it fixes the skin if you leave and re-enter the world.
EDIT: The skin jumbling was because I had a resource pack, but the whole changing skin to Steve after death still needs to be fixed.