Here is an article discussing the downgrade of the digital after Feb 2009. NBCU working to ensure that operators display proper aspect ratio with with receivers.

NAB 2008: NBCU Tackles Digital Downconversion - 4/15/2008 5:22:00 PM - Broadcasting & Cable (http://www.broadcastingcable.com/article/CA6551790.html?desc=topstory)

Thanks - interesting stuff - those of us in this Forum are concerned mainly about the other direction, so it was interesting to read that there are also problems in formatting 16x9 material for 4x3 displays...