The avengers movie?

okay i heard an avengers movie is coming out 2011 and i kinda beleive these rumors cause whats up with all these superheroe movies coming out the incredible hulk the dark knight iron man all in 3 months and thor is coming out in january another spiderman 4 is coming out in february tony stark made an appearance in hulk and also if you look closely when tony stark is building the iron man suit under his armpit you can see captain americas sheild