Occasionally, WordPress will log you out while you’re creating content. If you’re using P2, the AJAX polling code will give you a popup indicating that you’ve been logged out (and locks your ability to post a form).
Within the admin however, you can hit “Save Draft” and WordPress will redirect you to the login. This means you’ve lost all of your content. If you’ve been logged out for a while too, WordPress hasn’t been autosaving.
It would be nice to bring that P2-style notification to the admin.