Just a few days ago I brought you news of Wolfenstein: The Old Blood. The DLC is a standalone, so you don't have to own Wolfenstein: The New Order, and it acts a prequel to the main game. It's launching in May for $20.
It didn't take too long to see the DLC in action either. The game was shown at a PAX East panel showcasing pretty much what you'd expect. Lots of Nazi shooting. The footage, captured by Eurogamer, shows B.J. Blazkowicz infiltrating Castle Wolfenstein.
I like this new trend of standalone DLC. It's a great way to get people to buy the bigger game. I'd love to see this continue.