According to an article in Variety and this piece on Apple Insider, Amazon.com is planning on launching some flavor of direct DVD download service.
The new service, according to "sources," will likely work as a companion to traditional DVD purchases. From Variety.com:
The strategy is to not cannibalize traditional DVD sales while giving tech-savvy customers with video iPods and digital home entertainment centers the ability to use the content in the way that they want. Maybe. There's no word on DRM yet, but you can bet the farm that the content will be restricted in some way. Even so, this points to a further prying-open of the doors to digital content distribution of mainstream movies over the internet. Movielink and CinemaNow are already playing this game. We're guessing that Apple isn't that far behind, either.