I found the article by John Coie about using a computer program to help children learn to read most interesting. However, I object to the idea of placing such programs in preschools. There is absolutely no need to start teaching reading before children enter kindergarten.
In preschool, children are learning important social skills which prepares them for entry into formal school. At that stage in their development they should have the opportunity to learn by playing and experimenting and interacting with other children.
We should allow children to develop at their natural pace. Those who it turns out have more difficulty learning to read, for readily identifiable reasons, will have a hard enough time when in kindergarten and first grade without forcing them to try to read while in preschool, which may even make their problems worse.