Waiting list for limited capacity events

A logical and much needed feature for any event management is a waiting list for limited capacity events. I've seen only 2 threads in the forum and no solution so I'd like to revisit this topic and see if there's anything on the horizon.

How else would people be able to sign up when spots become available again? I can't send manually send out email notifications to everyone nor would people sign up for the event in the first place when there's no waiting list available, thus severely hindering the potential new member signups to the site to begin with.