I tend to wonder what story details were already planned out already at that point for the entire six movies and what details were not. For instance the looks that Obi Wan makes when he first sees R2 and 3PO (like he recognizes them) and also the expression he gives when Luke asks him what happened to his father. I have heard that Episode 4 was made mainly to be a standalone movie and the other two movies in the same trilogy had not yet been completely formed yet at that point and the prequel movie storylines were nothing more then a couple sketches on paper. But looking at some of the subtle expressions some of the actors made in the very first movie makes me wonder if the entire six movies weren't already planned out in pretty great detail already at that point. Or is most of those deals that we view as hints now nothing more than fans making more of it than was ever initially intended at the time A New Hope was made.