I don't know whether it's possible with wiki atch feature, but it is possible (and works excellent! with instant messaging. For instance: follow the tips on http://www.jabber.org/user/quickstart.php.
Which is: take a jabber client Gaim - http://gaim.sf.net is excellent, and multiplatform).
Take a free account at jabber.org, which is one of the free servers which offers rss feeds delivered to your im client. See: http://cmeerw.org/dev/node/7 to configure it.
Hope it helps,