What about something like how guild wars had? Or at least what i vaguely remember it had. Where friends lists and guild membership were based on accounts instead of individual characters. I don't really want that with guild membership though. Just maybe something implemented with the legacy system where your friends are associated with the surname they end up choosing. Kind of a keep it in the family vibe.
That was my only concern during beta. Me and a few friends I play with are notorious for having many characters at once and its a pain to chat especially when we are cross faction. I know we could just use aim or something, but it would certainly be more convenient to just be able to talk in game no matter which character we were playing. I'm sure people could argue that cross faction friend lists would be bad, but my desire to converse with friends trumps my RP factor. I'm sure some would agree with that while others don't. Both sides are valid there.
To me that strikes a balance between ease of building relationships/friendly rivalries and keeping the privacy that realid kind of destroyed.
So thoughts, opinions, flames....go!