JAL has posted its 737-800 configurations and routes.
Domestic - J20Y145 (J = Class J, not really Business Class)
International - C12Y132
First 737-800 will start operation from March 2007. Domestic routes will be:
Haneda - Ube (Yamaguchiube)
No International route announced at the meantime, but will enter service to China and South East Asia in 2007.