At WordCamp Orlando 2014, I presented a talk on the WordPress Theme Customizer. I am not going to repeat the talk in this blog post, but below are links to the sample code used in my talk along with some custom extensions I wrote for the Theme Customizer (including one to add the WP Media Library/Uploader).
WP Theme Customizer Media Library Extension with example code
David, awesome presentation. You did a great job. Thanks for posting the slides!