Count me among the mourners about the news of the Washington Post Book World's demise. Despite the relentlessly optimistic responses of Sarah Weinman and Jeff Pierce, Book World was more than its next incarnation as just another a Web books column would imply. People routinely carried it with them on buses and the Metro (it was a very handy size)—sometimes toting more than one issue at a time. They took it to libraries and bookstores as they tried to determine what to read (or buy) next. Its bestseller list was a cut above the others, as it would include a "Washington Is Also Reading" section, which was culled from local independent bookstores; these selections were always atypical and interesting.
Book World sparked spirited discussions in Mike Dirda's weekly book chat (which is also defunct). It was a nexus of literary events and culture in the Washington, DC, area. A dedicated section sends a clear message about the importance of books and reading (to which John Updike, God rest him, fiercely testified). Book reviews easily lost in the Style section—ie, amid Paris Hilton's latest antics and where sometimes you have to hunt for the Books column—hardly send a message of legitimacy.
I'm one of those people who curls up in an armchair with the Sunday paper and a cup of coffee; Book World was ideally suited to this activity. I don't want to curl up with my computer.