if you think about it, it is impossible for armor abilties to be in halo 4. halo reach was suppose to take place before halo 1, and the spartans on reach were using armor abilities. now i'm pretty positive that there were no armor abilities in halo combat evolved, like armor lock or jetpack. going through halo 1-3 there have been no armor abilities, but there has been equipment. if we find out in halo 4 that master chief had a jetpack, armor lock, sprint, etc... that wouldnt make much sense. i'm sure that everyone would be pretty upset to find out that they had any armor abilties throughout the whole series, but couldnt or didnt use them at all. therefore i think it will be highly unlikley that armor abilities will be in halo 4-6.