In case this also gets deleted here is a description of the trailer:
Now for the after-credits it's not a scene, it's a trailer for Avengers. It does not show much and its more screen flashes then anything else. It starts with Chris Evans punching a bag in the gym and eventually punches the bag so hard it breaks. Nick Fury walks in and asks him “If he is having trouble sleeping and tells him he has a mission for him. The screen says Next Summer. It shows quick shots of the the Avengers in costume around (with the exception of the Hulk) and Nick Fury tells them he has a mission for them. It then shows all of the characters one by one and ends with Thor throwing his hammer. Then Says May 2012 on the screen. It does not show the Hulk at all in the trailer just a brief shot of Mark Ruffalo. As I said the trailer was short, showing quick shots of the characters but it looked like Loki was in one of the scenes shown, but overall I cannot wait for next summer. Until then go see Captain America!
In addition to what's mentioned above, regarding The Avengers trailer, SHH user ComicGeek-86 adds on:
"When Loki is shown, it looks as if he's being escorted by guards (Shield? Something else? Not sure) And also, Tony Stark passes by Thor, patting him on the bicep and saying "That's quite the swinging arm you got going there" (Or something to this effect. Can't remember the exact wordage)
UPDATE: SHH have posted their description of The Avengers trailer, revealing a few tidbits not mentioned above.
We see quick snippets of Tony Stark and Steve Rogers, Loki being escorted in "handcuffs" by SHIELD. After that it's a long shot of Thor rocking a new outfit reminiscent of his Ultimate garb (sleeveless) in front of some roundtable of SHIELD. Then basically after that it's shots of action scenes - Cap in some sorta battlefield, Black Widow doing some flips and throwing darts, Hawkeye [and] a shot of Bruce Banner taking off his glasses.
A few months ago, CBM's very own WolvieCBM landed a scoop, claiming [Spoiler Alert] that "Thor fights Tony Stark (Iron Man) so he could get Loki back from S.H.I.E.L.D. possession." And with what's described in the trailer description above, it seems the scoop is somewhat confirmed. It also states that a huge fight scene where the Hulk and Thor are going at it in a city downtown. What do you think?