It would be very handy if students could get latest news forum updates, course updates, recent activity, quiz result, almost any course update (whatever can be reported on) via an RSS feed.
I suppose that the feed URL would have to include the course ID, user ID (or other unique identifier) of a valid and enrolled user and also to check that the course was available and so on.
Course tutors could choose which elements of the course updates can be shown within the feed (e.g. choose to exclude quiz results, for example, even if anonymous) but may default to show everything.