Curious about how your add-on will get along with Firefox 3?
Firefox 3 is coming down the pipeline along with a pile of great new features like caching web apps so they are available offline and the new Places API that provides a powerful interface to your bookmarks and history. No need to fret if your extensions will be compatible though - here's the lowdown on what it takes to stay up to date:
Want to know the big changes and what's brand new in Firefox 3? Check out Firefox 3 for developers.
Want to get right to the part about updating your extensions for Firefox 3? We've got a wiki page for that too.
If you know your extension will work and you just want to know what you need to do on AMO check out Justin's quick review.
If you'll be in Brussels, Belgium at the end of this month (February 23rd and 24th) you should consider hitting up Mozilla's Extension Developer's Workshop at FOSDEM 2008. It promises a trifecta of awesomeness including helpful people, Mozilla swag, and delicious beer.
Edit: update first link to be more useful