http://www.gameinformer.com/b/news/archive/2014/08/05/evolve-delayed-into-2015.aspx

Update: 2K has released a statement about the game delay:

As stated on the Take-Two Interactive earnings call, 2K and Turtle Rock Studios are extending the development of Evolve by a few months to allow enough time to fully realize the vision for Evolve and meet our collective standards of creative excellence. We are encouraged by the press reaction and fan excitement coming out of a very successful E3, and we are now certain we are headed in the right direction with the game and we are confident in delivering a genre-defining product when Evolve launches on February 10, 2015.

Original Story: Monster hunting will have to wait until the new year. Today 2K Games delayed the Turtle Rock developed 4v1 online shooter to February 10, 2015 via a financial statement.