For rentals, yes, I can understand a rise. However, to say that DVDs are on the way out? I don't think so. I download a movie I want to rent on my PS3. If I want to own the movie, I buy it. To buy and download a DVD is about 4 gigs. My movie collection would be huge! At least 4 TB of HD space, not including backups!
If I buy a DVD, I don't have to worry about running out of HD space, that is why buying a move for download will never catch on. I can delete a downloaded rental when I'm done.
As for Blu-Ray, it won't realy catch on until they hit the same prices as DVDs are now. I can buy a DVD dor 20 new (15 at walmart on the day it comes out) or 5-10 used. Blu-Rays cost 30+ new! The on;y Blu-rays I won are BBC scenic shows like Blue Planet, and Planet Earth. I don't pay attention to the details in an action movie, so I but the DVD.