All,
I just downloaded Emacs 24.4 and found that the function 'ad-start-advice was no longer defined.
I looked at the NEWS - no mention of the function being deprecated.
I looked at the "documentation" (comment section in advice.el) and all references to start/stop had been removed.
I looked through the past year and a half of the devel mailing list - and the only subject line that contained advice was the request to not remove advice documentation.
I'm not reporting this as a bug, because I can just update my code to work around this, but I do think that the changes made to this package could have been handled more gracefully.