8. Akiba-kei (アキバ系): “Akiba-kei” (lit. “Akihabara style”) refers to the geek culture of Tokyo’s Akihabara district, the otaku capital of the world. Synonymous with “otaku,” the expression generally applies to young men who frequent Akihabara and harbor a deep interest in idols, erotic PC games, model figurines and manga, although it can refer to geeky women as well.
The always interesting Pink Tentacle blog did a fantastic translation of the list that you should check out in any case. I'm particularly fond of the whole おバカキャラ trend; bring on more of them, I say. This is awesome news in and of itself, but with the way these things go, the term could just as well find itself on the list of "top annoying words of 2009"... oh well, glory be to akiba-kei and may 2009 prove just as profitable and eclectic.