Richard Sarnoff, chairman of the Association of American Publishers has speculated that Amazon and Google could combine to dominate the online book market (even more than they already do?), in the wake of the Google Book Search legal settlement:
Speaking at Princeton University's Center for Information Technology Policy, Sarnoff noted that Amazon currently dominates the market for downloadable e-books. He said that the settlement "forces Google to become a provider of electronic books with a different business model" in direct competition with Amazon. And he said that some aspects of the massive settlement would be "difficult to replicate" for Google's competitors.
There's some interesting discussion in there about how the Google settlement will dictate the way Google provides books to end users as well.