Rowan Collins wrote:
The basic problem is that people see the watchlist as private information - watching someone else's could facilitate anti-social users "stalking" those pages, etc.
(In reply to Brion's comment #2 http://bugzilla.wikimedia.org/show_bug.cgi?id=471#c2)
The tricky part with the watchlist is authentication
See my comment http://bugzilla.wikimedia.org/show_bug.cgi?id=471#c13 wherein I suggest a token method, the token only mailed on watchlist owner's request to his e-mail address, similar to Confirmmail method.
Having this information (i.e. the token), the correct RSS feed is delivered