Emily Lakdawalla on the Planetary Society blog posts about the Lunar Regolith Challenge. Mat Kaplan from the Planetary Society was at the event, and took some pictures of the challenge teams' machines that are posted on the blog.
The Planetary Society also has a half-hour Planetary Radio show that covers planetary science and related topics every week. The main topic of the week I just linked is "Digging for Dollars on the Moon: The Lunar Regolith Challenge". This episode of Planetary Radio goes into great detail on-site at the Regolith Excavation Challenge. The episode starts with an enthusiastic interview with NASA Centennial Challenge's Ken Davidian about the Regolith Challenge and the purpose of NASA's prize program. Next there's an interview with a NASA engineer who explains why NASA wants to learn more about excavating lunar regolith. Buzz Aldrin is there talking to the challenge teams and learning about their excavators. The episode then covers the teams' attempts at the challenge. Thanks to the Planetary Society for this detailed and highly recommended radio show on the Regolith Challenge.
See the "Regolith Challenge" link below for more posts on the Regolith Excavation Challenge.