There are new, videotaped, popular astronomy lectures available at the Silicon Valley Astronomy Lectures YouTube Site at: http://www.youtube.com/svastronomylectures
The site recently passed half a million views for its varied roster of talks by noted astronomers, explaining the latest developments.
New talks include a preview of the New Horizons mission to Pluto by team member Dr. Mark Showalter (who also discusses his discovery of two new moons of Pluto) and a discussion of the Planck Mission results (examining the afterglow of the Big Bang). Coming soon, a talk by former NASA Astronaut Ed Lu about the proposed Sentinel mission to help defend us against dangerous asteroids.