According to a post on Plextor Japan's website, the company has now transferred its entire drive manufacturing and sales business to Shinano Kenshi. While the Plextor brand will continue to be used, Shinano Kenshi will handle the development, design, manufacturing, sales and support of their drives.
This will probably have little, to no, effect on Plextor's American and European subsidiaries. If anything, we may see some new designs coming out of Shinano Kenshi instead of the rebadged drives Plextor is currently offering.