It has been well established that when a list of names starts scrolling up against a black screen, the movie is OVER. You're done. Whatever story you had to tell, you told it. That's the way movies work.
You want to put something cute after the credits, fine. Knock yourself out. A lot of times that stuff is fun. But it doesn't count as an actual part of the story. If it's something we need to know, tell us. Don't hide it after the list of gaffers and production assistants and humane society certifications.
Oh, what, at the end of the last Pirates of the Caribbean -- after the 37 minutes of credits have rolled -- it turns out Elizabeth has a son and is standing around waiting for her once-in-a-decade evening of romance with Will? No she doesn't, and no she isn't. Because the movie ended 37 minutes earlier, when the closing credits started. Whatever happens after that is just you horsin' around. Doesn't count. It's not canon.
What's that you say? After the credits of X-Men: The Last Stand we learn that Dr. X is not dead after all? Huh. Interesting. You'd think an important piece of information like that would have been included in the film, not as part of the previews for the next showing to be viewed by the ushers as they're sweeping out the theater.
Is there an appearance of a certain other Marvel character at the end of Iron Man? Why, no, there isn't. I watched Iron Man. I watched it all the way to the end, and there was no Nick Fury. What now? Nick Fury shows up AFTER the movie? Well, good for him! Too bad he didn't show up sooner, when it would have counted! Oh, well. Maybe next time, Nick! Try to be more punctual!
Cranky Eric® out.