http://io9.com/joss-whedon-bummed-that-marvel-brought-agent-coulson-ba-1699563630

Whedon revealed his feelings in an interview with Mental Floss (http://mentalfloss.com/uk/movies/28527/qa-joss-whedon-on-super-heroes-the-pop-culture-mainstream): "The Coulson thing was, I think, a little anomalous just because that really came from the television division, which is sort of considered to be its own subsection of the Marvel universe. As far as the fiction of the movies, Coulson is dead."

I like Whedon's work (I'm a fan of Buffy, Angel and Firefly) but he is certainly death happy. You can't go into one of his shows and not expect someone to die. As soon as I heard he was directing The Avengers I just knew there'd be a death in there somewhere. And I wasn't wrong, lol.