The DVD consortium absolutely cannot make this decision, contrary to what others have said. They sent a letter to the DVD CCA (Copy Control Association) in the USA supporting 625p last November, signed by 17 Consortium members and 4 UK DVD manufacturers, including Arcam, but to no avail so far.
However the (probably) good news is that the next meeting of the DVD CCA in a couple of weeks time has a motion on the agenda to get 625p "legalised" (i.e. included in the CSS - Content Scramble System - licence). I understand the studios do not oppose this. We shall see what happens.
John Dawson (Arcam)