It has been a tradition for Marvel to include spoilers in their post credits scenes and Captain America 2 is no exception. The film did not just offer one but, two post credits scene.

So who was featured and what was featured in Captain America post credits scene?

First Credits Scene:

Baron Von Strucker, played by Thomas Kretschmann, made an appearance during the first credits scene, where he is in an underground den having a conversation. A man approaches him saying, "It's over. Fury has released everything to the public."

To which Strucker replied, "Everything he knows about."

The other man added, "Mr. Strucker, if they get word of our work here...if they find out that we serve Hydra..." Strucker interrupts him, "Hydra, S.H.I.E.L.D., two sides of a coin that's not of a currency."

While Strucker was talking, he walks past a number of technologically advanced devices with workers in their respective work stations and computers.

Strucker, stops in front of Loki's scepter, where he continued saying, "What we have is worth more than any of them ever knew. We've only scratched the surface and already..."

Strucker starts to walk again while saying, "There are other facilities doing Hydra's good work around the world. We'll feed them to Captain America and his colorful friends." The other agreed saying, "Keep them off our scent. What about the volunteers?"

Strucker replied, "The dead will be buried so deep their ghosts won't be able to find them." The other man posed another question, "And the survivors?" Strucker smiled at him and answered, "The twins."

The camera then, turns to the man and the woman enclosed in two separate glass cells. The man is running around in his cell, slamming into the walls with his high speed. The woman on the other hand, is sitting on the floor and concentrating in levitating objects with her mind.

Strucker continued talking, "Sooner or later, they will meet the twins. It's not a world of spies anymore. It's not even a world of heroes. This is the age of miracles, doctor. There's nothing more horrifying than a miracle." The woman crushes one of the blocks she's levitating.

Judging from the first Captain America 2 post credits scene, the twins mentioned by Baron von Strucker, the nemesis of Captain America who leads Hydra, are Pietro and Wanda Maximoff, better known as Quicksilver and Scarlet Witch.

The twins will appear in Avengers: Age of Ultron, in the comics though, Quicksilver and Scarlet Witch are mutants and members of the Avengers. This will most likely change in the movie, as Fox owns the rights to all of Marvel's mutant characters.

The Last Captain America 2 Post Credits Scene:

A Captain America exhibit was featured at the Smithsonian museum, where uniforms of Captain America and the rest of his crew are being displayed. The camera focuses on a plaque with information about James "Bucky" Barnes. The camera then focuses on the man who is reading the plaque, and who's the person reading the plaque, it's none other than "The Winter Soldier" himself.

The scene most likely confirms the speculation of Steve Rogers that his bestfriend, Bucky Barnes, whom he thought who died in the train is actually "The Winter Soldier."

Thus, the story between Bucky Barnes and Steve Rogers will most likely to evolve in Captain America 3.