The word on the street is that Killzone 4 is to be announced at the February 20th press conference where Sony are expected to reveal their next-gen console, the Playstation 4 (or whatever they call it).
An industry source told VideoGamer that the game is expected to be announced as a launch title for the next Playstation, with both likely to land towards the end of 2013.
This most recent rumour comes hot on the heels of a similar report last week from STFU and Play, that suggests a shooter is about to be announced by Guerilla Games.