Fox 21 Television Studios is developing a new TV series based on The Dresden Files novels.
Previously, Lionsgate Television produced 12 episodes of a TV version of the books for the Sci-Fi Channel (now SyFy). The TV series was (very) loosely based on the opening books of the series, but were widely criticised for taking significant liberties with the background, lore and characters, as well as not faithfully adapting the novels. Particularly criticised was the decision to adapt the first novel in the series, Storm Front, as a movie-length pilot and then cutting it down to 45 minutes and placing it eighth in the running order, which rendered some of the plotting nonsensical.
Butcher has produced fifteen (of a planned twenty-three) novels in the book series since 2000, along with numerous short stories and comics. It's likely that any TV adaptation would adapt multiple books per season.
Fox 21 produces comments primarily for the FX Channel, although some of their shows have ended up on Showtime, Netflix and the USA Network. It'll be interesting to see what comes of this project.