About a week and a half ago, it was stated that Keith Giffen and Dan Jurgens are set to replace JT Krul on Green Arrow with issue #4.
Now, according to Newsarama, Giffen and Jurgens will take over Superman writing chores and layouts (and/or pencils) after #6 from legendary creator George Perez who may stay on as finisher/inker.
Perez has been doing both the writing and breakdowns on Superman, in addition to inking Jurgens on Green Arrow. I think a cover or two somwhere in there, as well.
No word from DC, or comments from Perez, as of yet.
Cosmic Book News will keep you updated.