The Ubuntu conferences of yore are set to return next year with the first UbuCon Summit on 21–22 January 2016.
The Ubuntu Developer Summit (UDS) for Ubuntu 11.10 Oneiric Ocelot is starting next week, running from Monday 9th of May to 13th of May. An exciting time in the Ubuntu calender year, UDS is where most of the important decisions are made for the next Ubuntu cycle. If you are an enthusiast or interested in Ubuntu 11.10, you might want to keep track of all the developments.
UDS-O - scheduled to be held in Budapest next month to plan the Oneiric Ocelot (11.10) release - hasn't even happened yet, but the location and date for UDS-P has been booked for later this year.