My first talk was on User Authentication with MU in Existing Ecosystems, all about integrating WP with LDAP/AD/CAS and other directory authentication schemes, as well as the hacks I did to make that integration bi-directional and deliver new user features. My slides are online (.MOV / .PDF), and you can read earlier blog post summing up the project.
I was most excited, however, to talk about Scriblio, a plugin that turns WordPress into a library catalog with faceted searching and browsing. Those slides are online as well (.MOV / .PDF). The core plugin is in the repository, but I’d recommend people join the mail list if they’re thinking of diving in to it.