MyWay, I respectfully disagree with your premise...here why. S:TM was done in 1978. There have been many children born since then. Most experience S:TM on HBO or Cinemax in the late 80's. There are generation of kids born in the 90's til date, that had never saw that film regardless of it being in syndication. The reason being, that generation see that, that film was made in 1978, have no desire to see such an arcade film in this era of the late 90's til date, with the advent SFX and better technologies of their era. Not to mention the fact that this continuity is a sequel to an arcade continuity of 1978.
With that said, we got an opportunity to see Batman's origin in the older films, and how it effected him on a personal level... making him the man/myth he is. We just wasn't afforded the opportunity to experience how proficient his training and skills came to be and how Wayne's Industries played a role in his technology and weaponry.
One can say the same for Superman. We experience some background details as an infant on Krypton, his livelihood as a growing child of the Kent Family on earth, and his first experience in Metropolis. Yet, we have not experience the uniqe life and similarities on Krypton that relates them to Earth, a full understanding of the situation that led to JorEl choosing to send him to Earth compared to other worlds, and the political intrigue that exist that may give a better understanding of significant correlation that ties Superman to a list of future villains(minus Zod). There is much in an origin story that we are missing that could be covered in the first moments of a Reboot, such as what happen in Batman.
Now, like most here and elsewhere, I royally like Brandon Routh as Superman and would hate to see him replace... which will most likely happen in a complete reboot. The way to get around that IMHO, is to do a Prequel. This would allow WB to give an origin story as I have discussed and maintain Routh as Superman for future installment. The Prequel could feature General Zod escape from the Phantom Zone and touch obviously on Lex Luthor. However, I would re-invent Lex as CEO of financial strap LexCorps, hence the reason for swindling the old lady's money, for his company and why Lex got off because there was no evidence or testimoney from Superman to link Lex to an invented crime in the confines of this new continuity.
WB just need to have imagination, creativity, and some profound understanding of the characters and their resources.