Nobody, that's who. Just a bunch of fans who continue to write this stuff and produce a podcast out of a love for the console. If you'd like to know the full story of this this whole Sega saga, feel free to digest the following articles published here at the Junkyard:
Below you'll find a nice retrospective video review of the Guide by regular Retro Gamer Magazine contributor Kieren Hawken.
To reiterate, there will be no further physical copies of this book produced. However, the PDF can be downloaded for free below and will occasionally be replaced with new and updated versions from time to time.