This is actually an extended version of a scene that Marvel already released, which goes to show you just how much leverage the promotional machine is going to get out of Avengers: Age of Ultron. Are we going to experience the whole thing in 10 second chunks?
At any rate, the prima nocta crack from Tony is pretty gross, secondly we see that Thor is pretty nervous about the idea that Captain America would be worthy, but lastly this is the sort of thing I wish was more common in these movies.
The Avengers as a team is filled with interesting characters and it's no surprise that "quiet" moments are often the first to be edited down, but watching these characters relax and just hang out is so much fun. We know how these people save the world, but seeing what they do on what looks like a rare evening off the hero gig is pretty interesting.
Also, every time we see Ruffalo playing up Banner's goofier side I wish more and more for a standalone movie. The guy has a lock on the character in a way that Bana and Norton were never able to pull off.
There's a fun bit of comic lore when it comes to Black Widow and the hammer, and it's possible the film is winking at us a bit by having Natasha be secure enough not to even try, but this is also a bit of evidence that every damned thing in these films is an Easter egg if you dig deep enough.
Now if we could get a scene where everyone tries on the Iron Man armor? I'd be good.