We're not anticipating any trouble finding a readership. Cheree Cargill did a multifandom zine called
Millennium for years. It started out as
Star Wars, but after a few issues discovered she was having a hard time getting submissions. About that time her love for
Trek got rekindled, and it made sense to her to go multifandom. Having started "active" fandom in
Star Wars myself I noticed certain patterns...like a lot of Han/Leia shippers were also into things like Buffy and/or Harry Potter, etc. And amongst the editorial staff of my zine, we love all sorts of things.
So we decided to go multifandom as well, covering sci-fi, horror, and fantasy, with the common thread that all three genres deal in things "otherworldly." What sets us apart from
Millennium , which is a gen zine, we've also established the commonality that all our stories are het shipper romance. At many of the media cons, slash seems to dominate, and we've often heard complaints that there's a shortage of het/gen zines out there, so we're hoping those people will like what we've done.
As for your question about writing across fandoms, yeah, for the most part we do. For the last several years I've been writing exclusively Han/Leia, but back in high school I used to ping-pong between
Star Wars and
Star Trek (Both TOS and TNG) all the time. I also fell in love with
Buffy the last couple of years, so I started writing that. The zine also gave me an excuse to rediscover old fandoms/ships I loved (like
Buck Rogers in the 25th Century), new favorites (
Doctor Who), and some obscure but good ones (
Hex). Skye and Seren did a
Robin of Sherwood zine for many years...and they've both written lots of
Star Wars and
Lord of the Rings. Seren's been writing up a storm in
Doctor Who lately as well, and Skye writes in an unrelated fandom called
Combat. Sue is primarily a writer of
Star Wars but she has a Spock story in the zine, too. Laura is our resident artist and she'll basically draw anything you ask her to, especially if it's romantic in nature. In fact I showed her pics from the TnT shower scene and she perked up and said "I can work with that!"

She likey some Trip, I think.

Our complete table of contents is listed
here, under "ordering information" You can see that we've covered lots of types of fandoms, from big and long-enduring, to relatively new, to small and obscure, to "wow, I haven't thought about THAT show in years!" We're hoping that folks will buy the zine to see their favorites, while taking the opportunity to try other fandoms on for size.