The Internet was just in it's early stages but it allowed me to track down an import of the soundtrack by Kenji Kawai (川井憲次). Kawaii wrote a lot of the soundtracks for Mamoru Oshii's animes, and also for the films of Hideo Nakata (中田秀夫) including Ring, Ring 2, and Dark Water. He is certainly one of my favourite Japanese film composers. Here are live versions of the main themes from Ghost in the Shell, and Ring.
I haven't kept up the Ghost in the Shell Series, Innocence, Stand Alone Complex, or the latest reworking, Arise. But something that drew my interest back to the new series was the soundtrack, since the original film's soundtrack was so memorable, I noticed that the new series' soundtrack was being produced by Cornelius the muti-facited mutli-instrumental musician who achieved fame in the late 90s on Matador Records. I'm not sure how Cornelius' eclectic style will match with Ghost in the Shell, he hasn't released a studio album since 2006s Sensuous, but has composer for TV commercials, and films. But you can check what he is doing for Ghost in the Shell Arise here:
Ghost in the Shell Arise 2 is in limited cinema release this week in Japan, and will be available later in the month on DVD.
Ghost in the Shell Arise website: http://www.kokaku-a.jp/index.php