The first Deus Ex: Human Revolution DLC has 5 hours worth of single player content. The main game took anywhere between 15-25 hours depending on your playstyle. So this DLC called The Missing Link seems to be a quite good.
“The Missing Link is approximately five hours long, but as always that varies depending on your playstyle and completionist urges,” said Eidos Montreal.
Official Description: “After being tortured by Belltower agents and having his augmentations disabled, Adam Jensen must rely solely on his basic capabilities to escape from a freighter, destined for an unknown location. While fighting for his survival on the ship, he uncovers another layer to the conspiracy that he never would have suspected. As Adam, gamers will befriend new, mysterious allies and fight ruthless enemies to discover what was happening in the shadows during the events.”
The game is headed to the Mac as well, so the DLC will be available on PC, PS3 and Xbox 360 along with Mac.