With Halo 5 for this year and Halo Wars 2/Gears 4 for next year, it does make me wonder what their big exclusive will be for holiday 2017. I could actually see them trying to quicken the output of Halo to a two year cycle as well. Or they may try harder to get third party deals for 2017 to hold them over until Halo 6 in 2018.
The big is Gears 4 only. Maybe Scalebound.
2017 I would bet is another Halo spin off.