My PlayStation Plus has helpfully informed me it has patched Spec Ops: The Line with an ‘additional content patch’.
This means the free DLC cannot be far away, in June 2K announced that the download would be available in August so it might show up in Wednesdays PSN store update.
The DLC will consist of four missions, each with their own objectives, environments and playable characters. You will be fighting waves of enemies and harsh sandstorms in areas of the game set before, well, set before something - revealing that something is a spoiler for the main game.
It sounds like this will be some sort of horde mode and free DLC is always welcome.