Hi there,
I just now found this site —and this question— while googling an old article of mine. Although the reply is 9 years overdue, I hope it finds the audience it was seeking.
Gateways ran as an independent pub for 13 issues from 1986 to 1989. At a time when The Dragon, White Dwarf and other general industry magazines were becoming company-specific house organs, Gateways stepped into the vacuum and covered all games and all genres. They specialized in franchise tie-ins (gaming had only recently discovered licensing), with a special focus on designers and creators.
(Just one example of the transmedia sampling the publication offered was a package on Speed Racer. It not only looked at the history of the cartoon, but interviewed the writer and artist of the new comic book, previewed the just-announced live-action movie —which would remain in development hell for another 20 years— and offered scenarios and official stats for including the Mach 5 in a half-dozen RPGs and boardgames such as Car Wars.)
Gateways also had in-depth (and inside baseball) interviews with industry personalities from Gary Gygax and Erick Wujcik to, well, everyone. I eventually wrote a two-part history of role-playing games for the pub, and talked to all but one principal designer in the business for the article.
The magazine reached its peak in 1988 when it gained national distribution. Sadly, it folded when a joint publishing deal with Palladium Books fell through in 1990 after only one issue (Gateways Special #1).
In a way, Gateways prefaced the current interest in transmedia, and its publisher went on to work with Disney, Sony and other corporations in coordinating the content in their movies, shows, books and games.