I agree that mabye the other poster was being a little harsh, but to an extent it is a choice as to wether you are willing to let the child CIO or not. I have worked child care and taken care of other people's children as well as my own for all of my teen and adult life, and have see a lot of children over the years with a lot of different personalities and sleep styles. I think that for the vast majority of kids if you teach them to put themselves to sleep at night and to put themselves back to sleep when they wake at night it solves most if not all of their sleep problems. I don't totally agree with the term CIO. It is really lore like giving them a necessary skill. For the benifit of everyone in the household kids need to be able to go back to sleep when they wake in the night without disturbing everyone else. Leaving a child to scream for hours over and over is not the answer, but nither is jumping evey time they wimper so that they never cry or get upset. It think that for most people a more moderate solution is in order, but one that is clearly difined and unchanging. i.e Mom will sit here in your room untill you go to sleep, but you will not get out of bed, and I am not going to hold you. The key is consistent, firm limits that do not change. Yes the child will probably throw a tantrum when you put you foot down, but that is all it is, a trantum b/c they didn't get their way. No emotional or physical harm done, and once they see that you mean business they will stop.
Children need their sleep and so do parents. I don't think that one person in a household, however small, should be allowed to dictate the rest of the house's sleeping patterns once they are perfectly capable of sleeping through the night without disturbing others. Everyone in the house's well being is equally important, and I good night's sleep is crucial to that.