This is seeming more and more like the only reasonable next move for publishers:
By foolishly insisting on DRM, and then selling to Amazon on a wholesale basis, the publishers handed Amazon a monopoly on their customers—and thereby empowered a predatory monopsony. […] If the major publishers switch to selling ebooks without DRM, then they can enable customers to buy books from a variety of outlets and move away from the walled garden of the Kindle store.
Unfortunately, it will probably take a good five years for them to realize that the basis of power for Amazon is the closed format insisted upon by the publishers themselves. The other wonderful byproduct of eliminating DRM would be the ability to share an e-book with a friend, something that is not possible now.