I would say that DD with a relatively decent internet connection generally wins out against leaving the house to go and rent a movie and the recent netflix statistics released which show more users getting movies through the internet vs dvd distribution support this. The convenience and quality factor doesn't side as positively for internet downloads against regular disc based distribution doesn't quite favour the internet as a distribution means yet however, although if the MPAA doesn't get their act together on friendly DRM free products they will continue to lose out.
The important killer app for DD isn't the speed of the internet, its the interface which lets you conveniently browse through a selection of videos. Natal is just as important for the Xbox 360s media download and rental services as it is for expanding the ways to play games and this device has seen an implementation as part of a TVs interface at a few consumer electronic shows.
Tease.
