So is there already code to support skins in PocketMine or is SOMETHING ELSE going to have to be coded in? https://twitter.com/_tomcc/status/507806426040111104
Well, skins aren't even added to Pocket Edition yet so PocketMine definitely doesn't have it. I am really excited for this feature though!
To add onto this, PocketMine may not need to run skins. It just depends on how Mojang depends on implementing it. If they implement it like PC version, it'll have to go through the server. However, the Android app BlockLauncher created a skin system that runs completely client-side, where the skins are taken from Mojang's database and added to players based on their username. Really, we'll just have to wait and see how Mojang plans to implement it.