I think people are blowing this a little out of proportion. I understand everyone's concern for their privacy, but this is absolutely no different than Facebook, where I can see someone's real name, but they can restrict me from seeing anything else. This is also just like Facebook in that if you don't want that information to be out there, don't use it.

You guys are coming at this as if Blizzard designed the system to screw you over. If you're not comfortable with your real name being visible to a stranger (like you do whenever you show someone an ID or use a credit card), then don't use the system.
I, personally, am not concerned that the roommate of my old high school friend can see my real name. That doesn't mean he has my email address or knows where I live.

I feel like giving you the option of an alias just turns this into another version of your friend's list, and I think the goal of this system was to make something that was a whole step above your normal friend's list. And I agree, it would be nice to communicate with internet friends across games, but that's not what this system is for. Maybe they'll add that feature down the line, maybe not.