One thought about real names: what does your contacts database look like on your phone? While I know a lot of people by their online handles, I also know their real name, and I typically choose to enter that real name into my phone. Maybe this is uncommon, but if not, if you're building a communication platform, it does make some sense for the user-entered data to follow this format. Is there some intrinsic reason that someone be referred to as "Jonathan Rockway" when you send them a message via the SMS protocol, but "jrockway" if you send that same message via Jabber? It then follows to wonder: if you're talking to your friends via YouTube, why would you use yet another nickname?
Maybe what people want is a unique identifier that only they know, and then choose to share a different name with different groups of people?
I don't have any strong feelings one way or the other, but I am interested in what other people have to say.