There's nothing on Stage really for players. It's a duplicate of one of the regular towns and is used for us to test features to make sure they work right before pushing them forward.
What are some of the features that have been tested there? I have been told that sometimes regular members were allowed on stage, that's why I wondered.
AKA Random crap Aikar and IcecreamCow have WorldEdit'ed in and blew up. I've seen spawns and stuff there blown up when Aikar was streaming during EMCon. And the members allowed there are part of the dev team, or at least that's what we were told in Mumble by someone. I forget who.