Seriously though, most people on this forum probably use Linux over BSD (and for that matter, their only experience with BSD was probably FreeNAS), so maybe asking him about the merits of BSD on the desktop would be a good place to start some good open discussion.
Also ask him how much his book weighs. He should know these sort of things.
No question. But I will miss hearing him talk about security stuff. As someone who's only in my formative years of using Linux (and very much enjoying it), I don't have the time or inclination to start learning about BSD, and therefore can no longer enjoy the Jude on a regular basis. This makes me sad :(
Also, I recently found out something (on /g/, no less) about BSD I never knew before... Namely, the fact that no one in the US has the right to "export" OpenBSD outside of the US?? Is that true only for putting up mirrors and alowing extra-USA parties to download, or does it also include having it on USB or DVD when trying to exit the country?