So, I am aware that (by this point) this is actually old news. It broke on twitter a few days ago, so everybody knows by now that Agent Coulson, played by Clark Gregg, is going to reprise his role on the SHIELD tv show that is going to be helmed by Joss Whedon.
While most of the fan reaction has been positive, I have seen a few people who were upset about it. Not because they had anything against Clark Gregg or the character of Agent Coulson, but because (they argue) this really destroys that moment in the Avengers where they all rally up and it's because of Coulson's death. Another person on twitter (I'm so sorry, I don't remember who) made the point that this is something that's wrong with comics all the time, people who die significant deaths don't stay dead. That this sort of thing 'cheats' his death of the dignity it had, and his badassery in his final moments. These are actually valid points, and should be given some consideration.
I... maybe I'm biased because I love the character so much (and the more I follow Clark Gregg the more I love him, too) but I don't think it's quite at 'cheating' levels. The medics move in and Fury tells the team he's gone, but Fury is the kind of bastard who would lie about this sort of thing. I think that is, largely, what spurred such a large segment of the fandom to declare that Coulson was, in fact, alive. (Even the Marvel Short that came with the Avengers DVD mentions him, and says something like "We all miss him," but he could still potentially be in recovery and not dead. An evil icepick to the heart is nothing to trifle with. Basically, we're dealing with a situation where a bunch of denial is entirely plausible.)
Really I think the judgement should be reserved until we know how Coulson is 'brought back', as it were. I personally think it will be fine- Whedon is nothing if not experienced with this. Not just bringing back beloved characters from the dead, but dealing with the repercussions of such a thing. Can SHIELD, as an organization, survive such a horrible lie? Or such a foundation-shaking resurrection?
There is also the somewhat disappointing but utterly realistic idea that the show will start at some point in the timeline before Coulson dies (or "dies"). I see this as entirely possible for more than one reason- they may want to save the real Coulson Lives moment for one of the movies. They may want to maintain that suspense a little while longer. They may want the character to actually die. We won't know until the date draws nearer how they're going to handle this.
It's easy to see this sort of thing as a victory or a loss for the continued Marvel film (and now TV) franchise, but Coulson so quickly became the heart of what brought the Marvel movies together that it would be a shame to permanently lose him as a character.