You know guys they could have made a worse ending:
Master Chief goes into the cryotube..a few minutes later he starts having a dream, he is a little kid, he sees a woman that looks like Dr Halsey. Something behind her moves and he instinctivly grabs his Assault Rifle, but its heavier than useally. Dr Halsey turns into the monster and attacks john, He wakes up hearing "Sorry for the quick thaw Master Chief but we're short on time.".....
Oh Em Gee I haz L00pd tiemcircle (because time isn't made of lines, its made of circles, that is why clocks are round.)