Well, here are a few ideas, mostly involving a roundtable type of audience par-tici-(say it, say it)-pation. (Thank you)
Modern CGI security practices, e.g. things you don't find in the FAQ's. (Of course, this could be mocked up into an Appendix to your web course.)
Commonly used regex's, why we use them, and where they fall apart? (I'd like to see this as a thread, personally.)
Unsung CPAN modules of my aquaintance. Things you might not have noticed. (Alternatively: What really needs to be a CPAN module?)
Perl 6 Discussion: Are you planning to use it? Why or why not? Are the Apocalypses/Exegeses helpful or frightening? What do you think is going to be the hardest thing to convert?
Q&A Time - Where are you stuck? Here's a roomful of people with a wide range of experience. Let's take advantage of them. (*heh*)
Future directions? What's coming down the pike in your projects? What does Perl need to help you make the impossible ones easier? What can we (the Mongers) do or cover that would help you the most?
I'm sure there are a host of other, possibly related ideas.
--f