Confirmed issue on skins in 14w34c on some computers. I see report of Beed28 on Minecraftforum.net :
"After updating to 14w34c, my skin is no longer working ingame. When I load the game, I either appear as the default Steve? skin or the weird abomination thing in the attached screenshot. My skin appears fine in 1.7.10."
My husband and I are also getting this... pink really looks bad on me. Black is fine... pink is just no.