There is always something new to learn, and if you have an enlightened employer, you should get some kind of training every year.  Here is a list of conferences you might be interested in.

Embedded System Conference - The only one dedicated specifically to embedded design.

Professional Developer Conference (PDC) - For microsoft technologies.  Lots of marketing stuff here. Also see the MSDN Events page for other goodness.
MiX - Another Microsoft conference, but this is geared to Web stuff
StarEast / StarWest - Software Testing Oriented conference.

No Fluff, Just Stuff - Java & Agile oriented conference. No marketing here! I just love the name!
Agile Conference - If you’re into agile development, this might be a good one.

If you think other conferences should be in this list, post a comment!