I know ones coming up.
No event has actually been confirmed, Game Freak have just confirmed Hoopa's existence.
But you can read a bit about it here: http://au.ibtimes.com/articles/579191/20150115/pokemon-omega-ruby-alpha-sapphire-hoopa-unbound.htm
Hope I helped. :)
On the official CoroCoro website, it talks about an event with Shiny Mega Rayquaza and Hoopa together. So I'm hoping it comes out soon.