I don’t know how recently this recording was made, but Dru Lavigne found a recording of Jeffrey Hsu (longtime DragonFly committer) taking about How To Get Started with Kernel Programming.
From the filename, I’d guess Sept 2nd, 2009, at the NYC BSD User Group :)
Your implacable detective work has paid off, sir.
The slides are there:
(will not be published)
DragonFly BSD Digest