With the delay of Driveclub there is a huge responsibility resting on the shoulders of Guerrilla Games and their Killzone: Shadow Fall as one of two first party retail releases for the PS4 launch (the other being Knack). At least it is now confirmed that the game is done and has cleared submission as game director Steven Ter Heide tweeted:
"#killzone #ps4 gold"
Going gold is an old and somewhat antiquated term for back when a gold master was sent out for reproduction back in the day. It's still used to signify when a game is done and discs are being copied, even if the process of getting certified is a little different.