Full disclosure: I have not attended the Summer Conference, but I have attended one-day workshops in the past.
I truly enjoyed getting to mingle with folks like Susan Swain, Steven Scully, and Brian Lamb on the grounds of C-Span's DC studios. The folks there do a phenomenal job of showing educators what kinds of great on-line (and often teacher created) education materials there are, like the Supreme Court timeline, the Constitutional Clips, and the Timely Teachable Videos that are periodically pieced together with great guiding questions. I have used these videos to teach about the Shutdown earlier this year, as well as the Occupy Wallstreet movement of 2012. There is also plenty of time to learn about the StudentCam competition.
(And the thrill of my life was dining at the Press Club downtown.)
Wow, that is a lot for just one day. I know that their summer conferences are well worth it, and who knows!?! Maybe with a little hard work, an application, and some luck you may be a Teacher Fellow who comes and lives in DC for the summer to try your hand at working at the C-Span HQ!