Also, trying to find more solid confirmation, but apparently Affleck shot down the rumors of him jumping ship at the WB SDCC panel. Said he loved playing Batman and was looking forward to working with Matt Reeves.
Joblo.com posted Ben's comment from Hall H on its Twitter feed. He was pretty damn convincing. He didn't necessarily say he wasn't going anywhere, but to quote he "would play an ape if Matt Reeves" wanted him to.