Canonical is going to host a Ubuntu 13.04 Developer Summit from 29th October to 1st November 2012. This event is going to be organized by Bella Center in Cophegen, Denmark.
The event will focus on new ideas, discussions planning and collaboration of the upcoming release. Developers not sponsored by Canonical can book a room in the Bella Sky Comwell Hotel for accommodation.
You can register for the event here. You can also find the Ubuntu Developer Summit Schedule here.
Ubuntu 13.04 is scheduled to be released on April 25th, 2013.