The only events I know of (as of Jan 2010) with Android content are:
- Google I/O - see the Google I/O wikipedia entry
- Google I/O for 2011 is coming up on May 10,11 in San Francisco.
- Embedded Linux Conference
- Some CELF Japan Jamborees have technical content related to Android
- Android Developer's Conference - March 7-9, 2011
- This seems to be the first full-blown Android developer event, covering mostly application development, but also some system talks
- Game Developer's conference is starting to see Android participation