Jennifer Jenkins has published "Last Sale? Libraries' Rights in the Digital Age" in College & Research Libraries News.
Here's an excerpt:
What's the difference between a sale and license? Normally, the law is skeptical of limitations on transfers of property. Can Snickers say you merely "licensed" that candy bar because there was fine print on the label? A court would be unlikely to agree. Can libraries argue that though e-books come with "a license," the library is nevertheless an "owner" with first sale rights? The answer at the moment is "probably not."