Just a suggestion -- once a post is saved as private, it is most likely going to stay private forever. Yet the big "Publish" button remains in the edit page. This is dangerous, as publishing a private post will make it visible, and even if you switch it back to being private, some RSS aggregators may have picked up the private content in the interim.
When a post is saved as private, it should be difficult to make it public -- for instance, only by changing the radio button in the "Post Status" box, and possibly with a pop-up confirmation dialog.
