Episode 1 of 3 of "The Genius Of Charles Darwin" aired yesterday, video up today on Google Video:
http://video.google.ca/videoplay?docid=-4471435322910215458&ei=12yaSJHfC5DQ-wHIw-0y&q=richard+dawkins+darwin
Haven't watched it yet, but I enjoyed his last two BBC series "The Enemies Of Reason" and "The Root Of All Evil," also both available on GV (I think).
Edit- I can't get the link to work properly, but the video I'm referring to can be accessed along the left hand side if you scroll down a bit. It's 48 min long.