Thanks to the internet, it's possible to acquire and read scripts for films that will never be shot, plots for novels that will never be written, and ideas for comics that will never be drawn. This is both good and bad, I suppose.
For one thing, it's often funny, as we have seen with the recent revelation of the Nick Cage/Tim Burton Superman Lives movie that never was.
For another, it's often tragic, as with the Superman 2000 proposal by Grant Morrison, Mark Waid, Mark Millar, and Tom Peyer. This Superman, by these writers, would likely have been magnificent. Alas, we'll never know if they could have pulled it off together. Actually, we have clues, as all of these writers have worked with Superman since then. Waid's Birthright was powerful. Millar's Red Son is one of the best-selling superman collections to this day (and one that every comic shop owner has pointed to as a constant favorite of customers), and Morrison's All Star Superman has been called "perfect" by a great many writers and reviewers.
So Superman 2000 didn't happen, but you can read about it. And lots of people like to write about it.
And I'm sure some people have incorporated this into their own idea of who Superman is, the residual image formed from all of their exposure to stories about him.