What happened to The Modern Humorist (http://www.modernhumorist.com)? 
They stopped updating about two weeks ago, and now their site is down.
 I'm looking for more than just WHOIS data -- I want some kind of
insider information here.

Hello.

I called the people at Humor Dynamics, the business-side of
Modernhumorist.com.
http://www.humordynamics.com/

They actually weren't aware that the site was down, but they said that
they'd recently changed servers so that might be part of the problem.
The guy with whom I spoke assured me that the Modern Humorist was very
much alive, and that he'd speak with someone in the technical
department and tell them to get the site up and running again as soon
as possible.

I tried the site 10 minutes later, and it's back!
http://www.modernhumorist.com/

search strategy: "modern humorist"

I hope this helps. Good luck.

Good answer.  I wish juggler would have asked the person he talked to
when Modern Humorist would be updating again, but it's a good answer
nonetheless.

Lazlo:
There's contact information at the bottom of this page:
http://www.humordynamics.com/

Give them a call. They seem like helpful folks and can probably tell
you more about future updates, etc.