Today the OST from Final Fantasy VII: Advent Children has been released in Japan. The box contains of 2 discs with a total of 26 songs. The orginal music is written by Nobuo Uematsu and has been arranged by Kenichiro Fukui, Tsuyoshi Sekito & Keiji Kawamori. The OST costs ¥3000 ($27).
For the tracklist look here: www.square-enix.co.jp/music/sem/page/ff7ac.