As we talked about Thursday, text on the net is ever-shifting. We can link other works directly, edit text immediately, and publish instantaneously (this blog is a testament to that). Slowly, the internet is incorporating all other aspects of how we communicate; such as books, radio, television, and even spoken language to an extent (ever use an online translator?).
Collections of material are making some of these originally static communication media into something that is constantly evolving. Books put online are now able to be translated, distributed, and read by people who were originally unable to receive or understand these works (often by volunteer fans who do this willingly and provide the author more notoriety for free). Although the books still stay the same thing (for the most part), they have undergone a complete format change from the original paper version.
These books can also be condensed, expanded, or edited in new ways. A writer can change a text in a whole new way. So, in a way, books as we know them are beginning to no longer exist in a concrete form.