Motoi Sakuraba - Star Ocean, Tales
Yuzo Koshiro - ActRaiser, Ys PC-88
Masafumi Takada - God Hand, No More Heroes, Killer7
Noriyuki Iwadare - Lunar, Grandia
Yasunori Mitsuda - Chrono Trigger, Chrono Cross, Xenogears
Dont forget Streets of Rage 2 for Yuzo.
Also with tracks like this, i'm not surprised:
http://www.youtube.com/watch?v=M5us0e8UNeo
http://www.youtube.com/watch?v=COgGsetFrCM&feature=related
After listening to the sample tracks, I have to say bringing in these composers feels like a waste if Nintendo's just going to make them compose generic orchestral soundtrack music like this. Sakuraba and Iwadare's contributions are rather uninspiring. Koshiro's and Mitsuda's are OK. Takada's composition is the only one that really stands out - it has a good sense of rhythm and fun interplay between the violin and guitar lines.
Twinbellows and Light vs Dark are not generic