I found this interesting because the video game industry is undergoing some of the same pricing issues that we are seeing in the book industry. Namely, the introduction of quality, inexpensive products is pressuring the traditional, higher priced products. Sound familiar?
http://games.yahoo.com/blogs/plugged-in/why-end-60-video-game-near-181412574.html

This is a trend we’re seeing in all entertainment venues. Word in the music/movies store business is that record labels are going to stop putting full albums out on CD soon.
You think the same thing will happen to paperbacks?
Not really. I think ultimately there will be less paperbacks published, but people on a whole are choosier about holding a real book than what they listen to their music from (CD, Mp3, etc.) That being said, might digital replace mass market paperbacks? Maybe. But probably not hardcover or trade papers, I would think. Those look too good on shelves.