He was also going to be on Flash for a long time too. Johns says one thing, then a few months later something else happens. The man has too many things on his plate, I suspect. And honestly, the quality of his writing has become very unreliable. His Shazam story was, in my opinion, amazing; easily one of the best things to come out of the 52 so far. But his Justice League? Totally lacks any kind of spark or sizzle. Its so bland I forget it exists until it shows up in my pull box.
I'd love to see him really embrace his role as a creative consultant and stick to movies and television. He has a knack for breaking a property down to its most basic concepts and cutting out all the excess. Its perfect for re-imagining characters (his work on Booster, Hawkman, Vibe, Green Lantern, and others all speak for this) but I find that he's sort of terrible with properties that dont need to be "fixed."