Even if downloadable movies take over, that won't make them better in quality than BD or HD-DVD. There's not much higher you can go in home video than 1080p, and it's taking people long enough just to upgrade to HDTV. By any other logic, we'll be turning around and doing that all over again in 15 to 20 years when something better, presumably 2k or 4k televisions, become available. Is there any evidence that it will actually happen?

This competition between the two formats is so intense because the studios realize that high def is it for home video, at least for quite a long while.