The hiring news fuels speculation that the developer is working on a sequel to Forza Horizon. The sequel is believed to be Forza Horizon 2 which will be an Xbox One only release that will drop in the fall of 2014. The release is timed to fill the space till the next Forza Motorsport is ready for release.
Forza Horizon came out last year and one was of the surprise titles that the company released. While we had heard that Microsoft and Turn 10 wanted to expand the Forza brand, Horizon was an attempt to do just that. While it was not a hit with everyone, it was one of our favorite titles released last year.
Since the release of Forza Horizon on the 360, Microsoft as well as Turn 10 have not talked about a sequel, but it is safe to assume that since they want to expand the Forza brand that there will be one. Rumors that Forza Horizon 2 will be an Xbox One only release might not agree with some, but Forza 5 is also a Xbox One only release, so it stands to reason that Horizon 2 will be a Xbox One only release as well.
See the hiring spree right here.