Atm there is:

Visibility / Sharing
Published (Public)
Protected (Members only)
Private (You only)
Draft (Not published!)
Deprecated (Not published!)

What i'm requesting is:

Visible for
Everyone
Members
Registered Users
Guests
You Only
---
Writers Only
Writers Only (Draft)
Writers Only (Deprecated)

With the above options being checkboxes.
You only overrides any other check boxes.
All your posts will be visible by you.
If Registered users is checked, but not members, the post will not be visible to members (even though members are registered users).
Actually maybe 'Registered Users' should be renamed to 'Non-Members'.
The 'Writers Only' options are same as the 'You Only' option, if one of them is checked, all the others are ignored.

This request would let users have posts like;
Benifits of registering,
Your not a member, Sorry,
Great your one of my friends!
Etc

I can help with the implementation of this feature.