There's a trend in people's writing and discussion of Superman, a trend toward imagining what a Superman would be like if he existed in the real world. We saw this in the previous post, where a couple of people imagined what Superman would be like drunk (if indeed he could get drunk) and how the character's politics and morality just wouldn't work. This goes back at least as far as Larry Niven's 1971 essay "Man of Steel, Woman of Kleenex" which delves into the problems of Superman's sexual relationship, should one ever develop, with Lois Lane. Since then, countless writers have engaged in this sort of mental exercise, treating everything from the sensibility and psychological function of the secret-identity to what he would do in his free time. Sometimes, this sort of thing makes its way into comics or television shows (and not just ones featuring Superman--go watch Mallrats for Kevin Smith's contemplation of super hero realities).
There's a sort of opposite number to this mental exercise, in which people imagine what aspects of the real world would be like in Superman's world. Famous examples would be meditations on what Superman would do if actually around for World War II, or 9/11. The example below comes from a galler at Superman.nu. The entire page linked to features fan art of Superman that reacts to the 9/11 attacks. This one was created by Ted Hernandez.
A corrolary of this is perhaps the imaginary casting of a Superman movie. Here's an example that reacts very specficially to the 2006 Superman Returns casting. It's one of those things that people do from time to time, but I've seen a lot of them recently. It may have to do with all the recent reporting on the legal battle over the rights to the character that has gone on between DC/TimeWarner and the Siegel family. It has prompted many rumors about when and if a new movie will go into production.