Gary Engel and Prestige Collectibles have announced the imminent publication of the latest edition of the Japanese Baseball Card Checklist and Price Guide. This latest volume is NOT labelled the Eight Edition. Instead, this edition is labelled as the "Vintage Edition" as it only covers cards issued prior to 1991. The book runs $30 plus shipping and can be ordered here. (There's also a lot more details about it at that link). Shipping should start around July 9th.
I sent an email to Prestige Collectibles yesterday to see if there were any plans to publish a guide for the post-1990 era (the BBM era) cards. I got a reply back from "Robert" who I assume is Robert Klevens, the owner of Prestige Collectibles who said "We might put one on disk in the next year or two but no plans to have a printed edition".