Two years later:
http://www.bloomberg.com/news/articles/2016-02-08/deutsche-bank-s-woes-threaten-coco-coupons-creditsights-says
kleinbl00 and I have been discussing these, which I have just begun to learn about. Scary stuff.
IMO there is a pretty good chance that we are all going to hear more about CoCos in the next few months.