I wish we would get off this "Singer expressed interest in a Superman Returns" sequel. We all know why one didn't happen. It's because freaking Warner Bros didn't want one.
We know that Singer has a different relationship at Fox now than he did before. The fact that he served as Executive Producer and was responsible for the story of "First Class" would indicate that he is still interested at some level with directing a movie. Not to mention the fact that he attempted to get out of his iron clad Warner Bros directing contact for "Jack the Giant Killer" so he could direct First Class. "Superman Returns" was a totally and utterly different situation. One that needs to stop being brought up.