Upon agreeing to do this presentation, I was offered the following advice for content...looks like a pretty good Table of Contents to me

•    A brief overview of the site from a business point of view
•    Why Drupal was chosen
•    Things in Drupal that helped you with the site, both core features and contrib modules
•    Decisions that were made and why they were made (even if it is "I did not know any better at the time").
•    Decisions that you would have done differently knowing what you know now
•    Custom code, and why it was done custom.
•    Complexity vs. simplicity, for example, does the site make upgrading modules a tedious chore? Have you mapped out an upgrade path to Drupal 6?
•    Hosting infrastructure
•    Security, PHP in content, ...etc.
•    Anything else you think would be interesting for a Drupal audience