Thanks to Gail Gauthier and her post, Why Blog Reviews Are Important. Yes, we bloggers sometimes post about new and upcoming books. But we post about books eight months and eight years and twenty eight years after publication, too. It's important for authors; but I also think it's important for readers. Depth in reading (and reviewing) is important.
Which is why my Best Books 2007 list is going to incorporate any book read in 2007, and I'll start noting the publication date.