What good does it do me to click on one of my real life friends and see that he's friends with some 'John Smith'. I don't see John's email address, I don't see his online status, I don't see any of his character names. If I don't actually know who this John guy is, it doesn't tell me anything. However, if I see that my friend has Jane Doe on his friends list, and I've been friends with her for years but never knew she played WoW, then I can send her a request and we can chat cross-server from time to time.

RealID may also have the side-effect of increased server transfers as people find friends playing on other servers they didn't know about, and want to join them .