I've read quite a few articles on dark energy and mostly found them wanting in terms of providing any kind of satisfying explanation. I suspect that it's difficult for many science writers pull off writing about something on the bleeding edge of discovery. The following is a panel discussion with some of the best experts in the world on the topic. I intentionally started the video at the 30 minute mark because that part is a lecture given by a guy that is hard to listen to.

http://youtu.be/BCUmeE8sIVo?t=30m