It seems the last week’s mega Halo 4 Leak was just the creative imagination of the forum poster at Bungie; probably a fan of the franchise.
As far as authenticity of information in that leak is concerned, Microsoft has denied any details communicated with media regarding Halo 4 apart from the teaser trailer revealed during their E3 press conference.
Responding to SegmentNext, Microsoft’s Dominic Carey, had this to say:
The only Halo 4 detail shared with media is the teaser trailer that was shown at the E3 Microsoft press conference. Nothing further detail on Halo 4 has been communicated with media. The forum post you refer to is speculative at best.
So, there you have it, you still don’t know anything about Halo 4 apart from what you can infer from Halo 4 Teaser. That could easily be called speculation…at best.