Seems so, here's a post from 2005 discussing it - http://www.satelliteguys.us/dish-network-forum/48642-pushing-back-mpeg4-turbo-8psk.htmlI believe they have been using at least that long. First supported with the add on module for the 6000.
Maybe a software upgrade on their end and ours and they held off until they made the ViP receivers the sole HD equipment source.