I recently read this book. I believe it would fall into the category of "paranormal romance," which I admit is not my genre, but I was deeply unimpressed. Essentially, it reads like a grown-up version of Twilight as written by Martha Stewart. There are vampires and there are witches, but they're highly romanticized and the political arrangements of the different creatures are more prominent than their powers. A promising story featuring paranormal mythology is road-blocked by pages and pages about the decor, food preparation, and descriptions of different wine vintages. Presumably the TV adaptation will be more dramatic, less domestic, and the characters won't spend 20 minutes at a time talking about what the wine smells like.
Also, I never saw evidence of the author's historical expertise at work; based on what little detail was featured, anybody who'd watched an episode of "Jeopardy!" could have written the same. I know the subsequent books involve time travel, so perhaps she shows her stuff there.
ProfStokes