Re: So, let's recap... E3
Keep in mind, that at this point in Halo 2's development we had just seen the "Master Chief exiting the space station" cinematic. In Halo 3's development, we saw the "Uncovering the Ark" cinematic. In Halo 4's, we saw the announcement trailer with Chief escaping the Forward Unto Dawn.
Halo 5 is right on schedule, based on the dev cycle of the other Halo games.