Dan (Thunder) and Seth, who not only share my interest for the Japanese language but also work on Places, the bookmarks system of Firefox 3 (since I'm now working on Flock's favorites system I have a great interest in Places)
...and a lot of other great people. Here is a few of the things that I learned:
rikaichan is a great Japanese dictionary extension, complementary to my baby Moji
Mozilla have one full time developer community guy (Mark Finkle) and one full time community-given program leader (Seth - his task is to distribute resources to volunteer contributors)
There are about 4 to 5 people working part time on Places. The back-end is the cool innovative stuff, going in Flock's direction (tagging, integral text indexing...) that they've always wanted to build, but the UI is conservative: the good old boring bookmark UI that you can find in Firefox 2.0. They will innovate from that after they get parity with the old bookmark system. However they don't use the URL as a key. If you bookmark the same page twice, you end up with two distinct instances.
Thanks a lot to all the Mozilla folks - that was a great day. I'm looking forward for the next.