This was floating around the Twitterverse, but JMS confirmed it a short time ago on Facebook:
As reported: with the huge success of the Superman GN, DC wants to fast-track the next one. This will require a great deal of care, requiring me to step back from scripting the monthlies to focus on this. Those stories will continue to their conclusion, based on my outlines. I’m also taking this opportunity to take a 1-5 year sabbatical from writing comics to concentrate on GNs and miniseries.
And he followed up:
Just to make it really, really clear: both Superman and Wonder Woman are going to be finished as intended. In a way, it’s no different than a situation where one writer plots out the story and another writer does the script, which is pretty common in the business.
DC figured it was important enough to their publishing plans to have me step back from the monthlies to do this, and I think that was the right call. I’ve already begun working with Shane on the next volume, and we’re on to some exciting things. But it’s going to take a lot of very detailed work, because the expectations for volume two will be even higher than volume one, so we really need to get this right.
In the last ten years or so I’ve written close to 200 published comics. In general, I feel I’ve done good work in the most of those monthlies, but where I feel I’ve done my best work has been in the limited issue/graphic novel format: Midnight Nation, Rising Stars, Silver Surfer Requiem, Bullet Points, and The Twelve (for which Chris has as of this past week caught up on the art, so now it falls to me to get the last bit done, so that can finally come out).
Taking a one-to-five-year sabbatical from monthly comics and doing instead only one or two GNs or minis per year means taking a 75% pay cut in comics, but I think it’s worth it if that allows me to tell better stories.
And if there are folks who are concerned about lateness in the monthlies, that concern is now erased. The GN’s and minis won’t even be solicited until they’re done. Anybody else willing to take a 75% pay cut to tell better stories…raise your hand.