Carl Zimmer points to news indicating that viruses are more lifelike than previously imagined - some viruses are physically active when they leave cells, instead of just waiting to bump into their next victim. More grist for the debate as to whether viruses are living organisms or just degenerate parts of living organisms.
The debate reminds me a little bit about the debate over what constitutes a planet: whether something should be considered alive, or is big enough to be labelled a planet, is not scientifically interesting. Understanding planets/planetoids, and understanding the behavior of things that reproduce, regardless of whether you consider them alive, are much more interesting questions. Zimmer is right that we're blurring distinctions, and that's just fine.