Michael said not once, but twice, that he'd love to return. With LoK, the casting direction, dialogue, and story is probably the one constant in all of the games. I don't think this series is something along the lines of Thief, or even Metal Gear Solid, where you can make a half-decent excuse to switch voices... there will probably be war if somebody tries to make a sequel with replacements for the current LoK actors.