Oh, I forgot to post my actual thoughts on it. Loved it. I know some think it's a stupid scene, but I think it's just so fitting and just so... I don't know... Whedon.
Love that Ruffalo is clearly trying not to crack, there's even a moment where Hemsworth looks at him and almost looses it himself - but manages to mask it by chewing more of his food (i feel bad for him after reading that EW blurb I linked to that he ate so much he almost made himself sick).
I kind of wondered where Loki was (since this obviously takes place after they've stopped Loki - Hulk has, after all, returned to Banner - but before Thor & Loki leave - unlike some, I have no problem accepting a post credit scene that takes place chronologically before something else in the movie). Me and my mom figured, Loki's probably just out of frame with Mjolnir pinning him down on the ground or something *lol*