Attached is a custom module that piggybacks on Unique Field and steals most of its other code from username_checkUsername Check.
Commit message: "Working Unique Field AJAX enhancement for node titles. Pretty sweet. It doesn't take away the duplicate warning when you change the title to not be duplicate, but it does change to a green checkmark (courtesy of the username_check module from which I also stole most of the code)."
Below, tales from