Yep, it was well-plotted out. They really did plan it from the beginning more or less. The commentary is worth a listen if only to see how someone handles an epic long running serial plot line with multiple threads - well.

I've seen it done poorly. (*cough*StarWars*cough*). It's rare to see it done well, usually someone drops the ball along the way. This one was done well for the most part -- also cast extremely well. They have a list of A+ actors in almost every single role, which is something that the other superhero franchise films failed to do, also Star Wars didn't quite achieve. Casting is very important, it can break or make a movie.