jimbeetle - 4:51 pm on Aug 23, 2013 (gmt 0)
I use living URLs from year to year, so after a recurring event expires, it disappears from all active navigation and taxonomy pages of the site, and a notice appears on the event page that the event has expired and we're awaiting the next update. But I do not noindex it. This is also what I do with recurring events where, say, this year's was cancelled.
I do exactly the same thing for an event site. One benefit is that I have 16-year-old internal pages still attracting a handful of links each year.