Another day, another e-book announcement. This time, it’s the widely expected unveiling of Barnes & Noble’s Nook e-book reader, which runs on the Android operating system and represents a frontal assualt on Amazon’s Kindle. Some of the most interesting news from the announcement, however, was in the atmospherics. Barnes & Noble’s press conference was attended by the CEOs of several major publishing houses, along with other publishing luminaries, who, “As much as anything…seemed relieved that Barnes & Noble, which operates the nation’s largest chain of bookstores, had produced a credible alternative to Amazon’s Kindle,” as the NY Times put it. But the announcement also hinted at bigger ambitions then merely offering an alternative to the Kindle. The feature that lets Nook owners loan e-books to friends with linked accounts, for reading on other Nooks or on mobile devices running the B&N app, suggests efforts to stitch together a broader Nook platform, spanning multiple devices and users. The publishers have obviously imposed strict limits on the feature for now, but it’s a step in the right direction.