I posted a topic called "Would Superman and Lois Lane make good parents?" a few days ago at the Superman forum on the dear, departed old DCMBs. The general consensus was that, while Superman would try to be a good dad (at least in the beginning), he would fuck it up due to his having to go off and save the world all the time. He'd also be pretty hard on the kid when he grows up to be as responsible as he is, I think.
And Lois? Fergeddaboutit! She's too hung up on her own career to ever think about raising children. She doesn't seem to have a nurturing bone in her body (not to mention a dysfunctional family with a father who wanted her to be a boy), so any kid she raises would be screwed up for life.