I've been able to successfully wait list myself a couple of times - supposedly wait listing is available to Golds and Plats, but occasionally I have been refused also. The idea is to keep trying until you meet with success/ get frustrated/ hit a wall.

Once wait listed, my experience has been that if they have unsold seats in J, EK will confirm the wait list 3-4 days before the departure date. See this thread for more info.
http://www.flyertalk.com/forum/emira...-ef-alert.html