When Marvel announced that it would be tying together all of its films with the intent of having them culminate in The Avengers, some people were skeptical. It seemed like a massive undertaking to weave together characters as diverse as Thor, Iron Man, the Hulk and Captain America. However, the company was able to pull it off, thanks in no small part to a certain minor character -- Agent Phil Coulson.
Played with affable charm by Clark Gregg, Agent Coulson managed to make his way into all of the Marvel movies. In addition to providing some welcome comic relief in installments like Iron Man 2, he served to remind viewers that the stories were indeed leading somewhere and would dovetail nicely in The Avengers.
Unfortunately, that culmination of the entire franchise saw Agent Coulson meet an untimely end. Interestingly, director Joss Whedon recently revealed at the New York Comic Con (according to /Film) that he will appear in the upcoming S.H.I.E.L.D. spinoff TV series. How this will happen and why Coulson is still alive has yet to be seen, but take heart from the fact that yet another major character from Marvel Films will tie this program into the shared universe.