I get that it would be an added layer of indirection, but to allow each user to have multiple subject personas for posting and let others subscribe to said personas might have been more useful. As it stands, I err on the side of caution and post privately to the people I can best guess might be interested.
Don't Pages let you do that?
For myself my inbox has essentially two folders. Inbox and Archived. My facebook lists is just friends and my google plus circles is just whatever the default is.
I don't want to think about who I'm sharing things with. I either share it with everyone on a social network or send it as an email to specific people.
But, instead, I find I just share everything I care to share public. I think what people share is part of how they present themselves, and if I'm always in the context of being myself, with my real name and the same picture, then I'm going to share the same set of stuff.
Put down the crack pipe and step away from from the whiteboard.