I think it will be more than a few years. There are still going to be way too many people without fast enough internet connections or internet connections altogether for a long time. Maybe they could pull it off in Japan in a few years, but North America? I don't see how.
I like to collect some things, and I'll be disappointed if physical media dies off. And it's so nice to be able to loan people movies. Also, if the whole industry can't agree on one form of physical media, how are they going to agree on one download service? I foresee a bigger mess with downloads than could ever take place in a war like that between HD DVD and Blu-ray Disc.
