A new WordPress plugin called seoslides aims to bring slides straight to your WordPress website. Alorum worked with 10up to build seoslides. You can build presentations right in the WordPress admin using a fancy HTML 5 canvas interface, and you can import slides from other websites, PDFs, PowerPoint, Keynote, etc. The plugin is free with a paid upgrade of $200 per year. It's a bit expensive for your amateur speaker, but perhaps a good deal for those who frequent speaking circuits.
I played with the plugin, and I can tell it's a beta release, but it's definitely promising. Kudos to the team at Alorum and 10up on building something that solves a problem and uses WordPress in an interesting way.