I wonder how many people thought "Hey it's that Arrow Guy from Smallville in Avengers" ? Actually I think I read on here about someone who's friend wondered where Superman was
And LOL at "it will probably be based on it in the same way that X-Men 2 was based on "God Loves, Man Kills." In other words, inspired but a liberal adaptation."
You could also say Dark Knight Rises was inspired by "No Man's Land" but too was loosely adapted. Still they both turned out to be cool movies. So maybe having something to ground the story on before taking off is a good idea.