MPEG 4 has been demonstrated to be a superb standard but to try to implement it now would really alienate a lot of people who just made big dollar purchases of what would be potentially obsolete equipment. At the very least a TV would become a monitor with the need for an outboard decoder of some kind. And I don't think broadcasters are interested in spending the money to convert, especially in these economic times. I believe it will be some time before we see a change like that. (But I've seen crazy things happen in this business, so don't remind me of what I said if something develops real soon ;-)