The second book in Mira Grant's Newsflesh series is just as compelling as the first, though I don't like the narrative voice quite as much. (It's a boy.) This time the focus is less on media (though of course blogging and fancy tech are still major elements) and more on medicine, medical ethics in particular.
My one criticism is that while the events of the book are dire, and the characters react to them as such, I wasn't entirely caught up or very horrified at the big bads that occur. I'd like to believe more and be more emotionally engaged.