I was going to add the same thing. I was following this when the news broke in 2011 (both Popular Mechanics and Science News had mentions) but nothing since. Since it hasn't gone black (aka 'secret') and has fallen off the "projects" page [1] of Mueller's lab, I'm guessing it doesn't actually work.

[1] http://www.egr.msu.edu/mueller/

EDIT: Found another article [2] that suggested late last year there was supposed to be a 25KW exemplar. Since its now close to the end of the first quarter of 2013 and there isn't a press release, I'm further convinced that their ended up not being anything to talk about.

[2] http://beforeitsnews.com/science-and-technology/2012/08/wait...