Small update I found via Freedom to Tinker:
It's the Princeton University Store, a bookstore that is located on the edge of the campus but is not affiliated with the University, who will be the entity offering DRMed textbooks.
Not that it would make a big difference in regard to how these textbooks are introduced (DRM), but at least it puts Princeton's name into a better picture again
More:
http://www.freedom-to-tinker.com/?p=881