Re. heat vision....Supes eyebrows "angrily" tense in proportion to the heat being used.....the intensity of the glow in his eyes grows rapidly, before fairly thin red beams are emitted, acompanied by awesome sound FX to simulate the burning air(whatever that sounds like?). Perhaps when being used at maximum power, a very subtle recoil by Supe's head as they fire. They always converge at Superman's target, just as our eyes focus at one point.
Something that it seems has become lost in the CGI/3D world of filmmaking is, sound FX. I can't think of a film recently that has featured a signature sound. Examples of a signature sound would be Tarzan's yell, Darth Vader's breathing, the sound of a light sabre, etc. You hear it, and instantly recognize the source. A lot of time and expertise for Star Wars and Tarzan's yell went into inventing sounds for devices and actions that don't exist. It would seem that the sounds of Superman would also fall into this category. A recognizable sound for Superman in flight would be nice. These types of FX are IMO of particular importance to a franchise film of which I hope Man of Steel will become.