I was under the impression that even though Michael Gondry had taken over directing duties on THE GREEN HORNET, Stephen Chow was still going to be playing Kato. Maybe not. Cinemablend caught up with Seth Rogen at SXSW and when they asked him about it, he responded that:
"We have no 100% official Kato at this point."
Of course, Chow could still end up taking the role. It just hasn't been confirmed yet....