Personally I think that with there being so many Superhero films and remakes about these days, something has to be very special to stand out from the crowd. Superman is the daddy of all superhero films. I loved the Reeves films (well, I and II anyway) so I think for any remake or reimagining of such a character it needs to be different from what's been before. Big set pieces and up to date SFX mean pretty much nothing. They certainly won't be remembered the day after you've seen the film if the story and script weren't super (sorry the pun) tight and it wasnt intelligently done with endearing characters. Which goes for any film, regardless to it being a fantasy film or not. Recently, TDK trilogy has been the barometer for superhero films for me, but Superman is an alien so its going to be that much more difficult to make him a grounded character you can actually route for aside the usual, "yeah kick his ass Superman!" The trick is to make the characters around him endearing and believable for it to work.