Coming Soon says:
Following up on last night's post, scooper 'KapoMonkey' has now given us a description of the scene you'll see after the credits of Captain America: The First Avenger. Read on if you don't mind finding out beforehand...
The after-credits 'scene' is not just a scene, it's the actual teaser trailer for The Avengers! Here is 'KapoMonkey':
The breakdown of the after-credits scene from what I can remember:
Steve Rogers is in an empty gym throwing haymakers at a punching bag before finally punching it so hard it breaks off it's chains and (I believe) through the wall. Nick Fury walks in and says something along the lines of "getting ready for the enemy?" and Steve goes "Well it's been awhile."