The only post i've seen is that you get 1 set of wings for your account, if you want to wear it on another character you must put it in the stash and trade it.
As far as hardcore, i don't know what happens to them.
Bash did say this, but he then came back and told us he had made a mistake, and you actually get a set of wings on each new character you create.
You don't have to worry about losing them on hardcore, because your new character will get its own new set of wings.
oh thank sanctuary that's true!