As a newcomer to the Dresden Series, I have never had to "wait" for the next book to drop.  I consumed the entire "audible" series over the past year, and finished Battleground over the Thanksgiving Holiday.  So... I wait.

Will I have a longer wait if I want the audible version of Twelve Months, or will they drop on the same day?  How long does it take to create an Audible version of a new work?