Nearly every OS4.1 machine already has DVD hardware acceleration, its just nobody had time to enable it in the drivers yet so why would somebody bother to write a driver for a seperate card when they could just improve the driver for a card everybody already has (because the few people with access to them are very busy)
I do wish people would stop claiming the Sam doesnt have have the power to play a DVD, i used to play DVDs with no frame skipping on a 300mhz AMD K6 (not K62 so no 3DNow and 66mhz bus) 66mhz SDRAM and a PCI ATI Rage 128. if that could do it then i'm sure a SAM can with the right software :D