I do see people eventually buying new blueray titles instead of DVDs once the prices are comparable.
The only people who will be buying Blu-Ray movies down the road are the same people insisted on Laser-Discs forever.
Online distribution is going to annihilate the DVD home sales market. Just decimate it. When companies transition to sell their movies to consumers without spending tons of money making a physical product, and just load it straight onto their computer for $1 or $2, physical media is going to be obsolete.
Remember how we each had an email program, like Eudora, to download our email? Gmail? Yahoo Mail? Almost every mail provider is storing this stuff for you remotely now... (which has it's own risks) Remember how we used to load our photos on our computers to save? Flickr anyone?
How long will it be until you can watch any movie you want on your iphone for a fee? (legally...)
Blu-Ray is not going to appeal to the vast majority of consumers going forward. They won't even need DVD players anymore, or any player for that matter. Their cable box will deliver whatever they want.