Wow.. what an amazing scene. Really shows a core aspect of modern day Captain America, a man out of his time.
Brilliantly written, shot and acted but i can understand why it didn't make it into the movie. Avengers was a high enegergetic movies, things were always happening and there was no time for background, emotional character pieces.. everything was geared towards getting the story along.
This kind of scene would be perfect for the Captain America movie sequel though which should deal with him coping with the modern world and how out of touch he is.