It has been very productive this week working at Brian's place in Seattle. No sightseeing this trip but had an enjoyable experience talking with other developers and users at the MySQL meetup session.
I have been working on developing a flexible Log Plugin system which hopefully does not have the drawbacks of the existing system. The new code seems to be working well now although it is not tied into any system variables in a way to show off what it can do. My patch earlier on Wednesday replaced about 2500 LOC with about 500. Even after the code written today, there is still a significant reduction in the overall code size. Now, all I need is my plugin server variables patch pushed...

An interesting but ambitious idea would be to refactor the mysqld code in a major way: Not just a minor tweek but would take a lot of the concepts, libraries and design of mysqld and put them together in a cleaner way with the benefit of hindsight, wishlists and the goals of mysqld. Very possible to do but not at all easy.