Player Skins and multiple players

I saw a forum post and a resource which shows how to apply multiple skins to player models, but it was a large modification and I'm just wondering if any of those changes are in the recent head builds by default. I noticed some skin pref code in the .cs files but I'm not sure if they are functional or how to use them.

Also, I've created my own player model, how would I go about switching between it and the default model in game? I can't seem to find any resources on it.