No, he's not the centerfold.
Whew, thank heavens. I knew they were accepting just about anybody into that rag these days, but sheesh.
The latest issue of Playboy has an article about how comic books have become mainstream and part of adult entertainment. JMS is quoted a few times.
I may have to read it. JMS has written for Amazing Spider-Man and Fantastic Four, two of the oldest titles still in production. One of his Spider-Man storylines raised a few eyebrows among readers, and even garnered a letter-writing campaign (although one has to wonder just what the point of that would BE, exactly). He did an interview a month or two ago explaining why he did the storyline, and how, in the end, he really changed nothing about Spidey's history. He only used it to explore a little bit "outside the box."
JMS is also responsible for Spidey's new costume designed by Tony Stark (Iron Man). Again, eyebrows have been raised, but JMS has made it clear that the costume change isn't necessarily permanent.
I loved the 9/11 issue of Spider-Man. I've read most of the issues he's written, and I really enjoyed his Fantastic Four issues. They're all very JMS-like, in that he takes what we know and then shows us how it looks in a much bigger perspective.
He also shares his opinion about the 1989 Batman movie, saying that he thinks Burton really wanted to make a movie about The Joker, not Batman.
I can see how this would probably be true. Batman isn't the most interesting character in all of comicdom. He's dark, he's angry, he hides his pain, and this is why he literally can't stop doing what he does. There really isn't much more to understand about the guy.
The Joker, on the other hand, is a very dynamic, creative, and most of all unabashedly evil person. He's always been the bad guy who creates toxins to make people laugh themselves to death, or drives around in a car with a big clown face on it, but there are many more layers to his twisted psyche that writers are just now starting to explore.
It's the April issue, with the wrestling chick on the cover.
Who looks nothing in person like she does in this month's Playboy. Playboy's Photoshop minions do so much airbrushing these days, it's ridiculous. She's gorgeous in person, so I dunno why they feel the need to go overboard the way they do. Whatever happened to the old days, where you just used proper lighting? (That goes for a whole lot more than just Playboy these days too...)
And he was the only interesting part in the movie. 
