Kohsuke just posted a brief write-up on his personal blog about the first day of the Bay Area Hudson hackathon/meetup. He writes:
Total of 9 people came and we had a great time talking about infrastructure issues, possible enhancements, design dicussions, exchanging tips and plugins that they've developed, and otherwise building personal relationships.
A number of folks joined us on the #Hudson
IRC channel on Freenode and the WebEx conference, participating remotely. Since day one was primarily intended for hacking on Hudson itself, we're expecting more people tomorrow when we'll have a good mix of folks hacking on Hudson, folks hacking with Hudson and plain old folks.