Hey caroth! Actually, I think the old version of chat mod still works, except for CP configuration.. so don't modify every file which begins with "cp" and it should be fine..
I was actually making a chat mod for 6.6, and might continue making it soon, but it's a big project to make it compatible with the new CP.. (not because it's difficult to program it or something, just because you have to copy and paste wordlets and stuff so many times :/)