The Delirium series does not have a new book coming out soon. The latest book, Requiem (Book 3), was published in March 2013.
The first book in the Delirium series, Delirium, was published in February 2011.
The Delirium series primarily falls into the Dystopian and Science Fiction Romance genres. This young adult series was written for ages 12-17, but can be enjoyed by adults too.