I think they need to let Superman rest for a while and push their other characters like Flash, Green Lantern, and Wonder Woman. Marvel is putting out way more characters. DC has a rich background. Yes, Supes and Bats are the foundation characters, but DC/Warner Brothers is doing a disservice to themselves and the fans by not really delving into the deep well they have.
I think a follow up the disappointing SR won't be all that exciting, and a reboot so soon after SR might go the way of Incredible Hulk in terms of popularity.
Though I would prefer getting rid of Singer. He had his chance and he blew it. I don't want to see a retread of TWOK which is what I heard he plans for the Man of Steel sequel. At least look to the vast amount of Superman product out there for source material. Why go back to TWOK? It worked for X-Men 2, but I would like someone willing to be a little more creative yet stay true to Superman's character and the mythos. A little tweaking is fine, but I didn't care for Singer's changes, or his casting choices. Though Spacey was an inspired choice for Luthor, Singer didn't really do anything with him. And Routh was told to mimic Christopher Reeve IMO, which was only a reminder of how great Reeve had been in the role while doing nothing to allow Routh the opportunity to put his own stamp on the role.