The voice of Master Chief has let slip that Halo 2 Anniversary will be released later this year.
Steve Downes who voices Master Chief said the following to Game Zone:
I think you may be ahead of yourself on Halo 5. Downes said. I wouldn’t expect anything until 2015. What you can look forward to this year is an anniversary edition of Halo 2.
Halo 2 Anniversary is expected to be released for the Xbox One. It will mark the tenth anniversary since the original came out on the Xbox back in 2004.
You will have to wait a bit longer for Halo 5. This might be a good thing in the long run as it means the game will have a longer development time.