Nah, the article (and the claim of the inventors) were very misleading. Soon after this publication, more detailed interview to the inventors were reported, and the inventors admitted that they use metal oxidation process to produce H2 from the given water. So it consumes that metal in order to produce electricity (and it also produces metal hydroxide as waste). Calling the system as "generates electricity with only water and air" is almost a fraud, imho.
I couldn't find English article of the interview. Here's a link to the Japanese one.
http://techon.nikkeibp.co.jp/article/NEWS/20080613/153278/