Otto Wood has created an initial version of a WordPress theme intended for use as presentation slides. It’s called Slides. Hosting slides on the web makes complete sense, and making slide templates WordPress themes is just as logical. I can completely imagine using a Multisite install where I can have a site called my-talk.krogsgard.com for a presentation. The entire site is the presentation. Be sure to check out the details of Otto’s post, it showcases a lot of flexibility in the theme for customizing your presentations.