Due to the popularity of Cortana, Microsoft began work on making Cortana a virtual assistant on the Windows Phone 8.1 operating system. It has been confirmed that the voice actor of Cortana in the games, Jen Taylor, will provide the voice for the virtual assistant to appeal to fans of the Halo series. Microsoft plans to release a beta for Cortana in April of 2014. Microsoft is also planning to have the Cortana virtual assistant on the Xbox One and Windows 8.1 (unless newer version is released) computer/tablet devices in 2015.
(The final build will use the actual voice actor for Cortana)
As a Microsoft fanboy, I can't be more excited for this. My Windows Phone, PC, and Xbox One just got more amazing.