With only a few hours to go before Microsoft's E3 press conference during which Halo 4 would have been a huge announcement, as would Halo HD both from 343 Industries Microsoft's Xbox.com site has outed both titles.
The leak or as we like to call it when content management systems screw-up and people yell about broken embargoes, "Screw-Up" reveals (or rather revealed as it's now been removed) that:
"The news millions of Halo fans have waited for: Halo 4 is on the way. But thatís not all..."
The tag there also refers to Dance Central 2 apparently, as well as Halo: Combat Evolved HD and Kinect Sports: Season 2.
Of course, this could all be a huge joke at Sony's expense given the latter's tradition of leaking everything pre-E3.
But it's more likely to be a cock-up.