If thats the case why not swap all existing channels to MPEG 4 System by system. The new boxes have MPEG4 built in. The old boxes have to be at their end of life cycle anyhow. They would see a 4:1 bandwidth increase when it comes to HD channels. That's more conservative. They could easily get a 6:1 increase in HD channels if they package 720P and 1080I channels correctly.