I would assume that the video effects are preformed on the Leopard side, and then just sent pixel by pixel, so it really wouldn't have an effect. I would think that if you can do video chat with aim, you can do any type of video chat with aim(with the exception of screen sharing).
Walt Mossberg (sp?) the Washington Post guy said video chat, including the background video replacement feature worked with AOL. He didn't mention anything about documents, presentations etc. which I assume didn't. Still happy to have video!