This list is meant to capture upcoming events that the Wikimedia Mobile projects expect to have presence at along with a longer listing of industry mobile events.
Upcoming events 
- India 2011 hackathon focused on Internationalization, Mobile, & Offline
- San Francisco - January 21 and 22, 2012
- Brazil 2012 - Proposed hackathon
Mobile Conferences 
Where to meet mobile developers, vendors, operators... potentially interested in Wikimedia projects. Note the many events happening in USA and Germany, where Wikimedia communities are also strong. Not a coincidence.
- 10-11 May 2011 Google I/O - San Francisco.
- 11-14 May 2011 LinuxTag - Berlin. Might be useful since Wikipedia community & mobile devs are strong in Germany.
- 23-25 May 2011 MeeGo Summit - San Francisco.
- June 2011? Apple WWDC - San Jose?
- 23-24 June 2011 Mobile Developer Summit - Bangalore. Wikipedia & mobile are big in India - probably also a chance to meet developers for lower-end devices.
- 25-29 July 2011 OSCON - Portland. Fits in the openness spirit + web & app developers can be found there e.g. Android friendly.
- 6-12 August 2011 Desktop Summit - Berlin. GNOME & KDE devs plus some of the best Linux app developers, including mobile.
- September 2011? Nokia Developer Summit (URL from last year) - ???.
- 8-9 October 2011 Silicon Valley Code Camp can be fun!
- 9-11 October 2011 Oreilly Open Android Conf Oreilly Open Android Conf
- 18-20 October 2011 Blackberry Developer Conference - San Francisco.
- October 2011? Microsoft PDC - Windows Phone doesn't seem to have yet a conference on its own.
- 1-2 November 2011 Smart Device & Mobile User Experience Summit... Was OSIM before. Might be useful to meet vendors, operators etc.
- 7-9 November 2011 AnDevCon aka Android Developer Conference - San Francisco?
- Autumn 2011 - Qt Developer Days in Munich & San Francisco (URL from 2010).
- February 2012 Mobile World Congress - Barcelona.
Also worth considering: there are many mobile local events in SF Bay Area where good advocacy might bring good returns. http://meetup.com is a good (non-free) service to trace them.