I would like to be able to subscribe to a documentation notification change subscription service - selectable by product - so that I can get an email as to when there is a change or addtion to a manual, white paper, or KnowledgeBase article. So, for example, if a manual changes or if a new KB article appears I'd get an email. I'd be able to select daily, weekly or monthly as options as to when I'd receive the notification.
Email would be one method; RSS might be another.