:lol Even if he wasn't baffled by date formats, how do you jump from a date being 4 days after E3 to "OMG THEY ARE ANNOUNCING A NEW CONSOLE AND H4 IS A LAUNCH GAME".
That said, I think we may see some new hardware at E3, here's my prediction:
Microsoft announce a new interim Xbox, called Xbox Lite/Light. It's smaller and quieter than the 360 S. Crucially it does not have the same guts. Y'know how H4 has been looking "smoother" than any 360 game we've seen before? I reckon they're announcing a new Xbox which improves graphics at a hardware level. Native 1080p, FXAA, no frame drops or screen tearing. I doubt it'll give a higher framerate as that has gameplay implications, but it should lock the framerate. Essentially it allows games to look and run better, but doesn't add anything to them, all games will work on both consoles they'll just look beter on the 360 Lite.
Releases day and date with Halo 4, along with a Halo 4 Legendary Edition console.
We then get a campaign video of Halo 4 showing the first level and cinematic (no mention of who the new enemy will be), followed by Spartan Ops live demo. Spartan Ops to be playable on the show floor. They'll release a multiplayer trailer a couple of days after the main conference.