Genetic engineering and gene manipulation; good or bad for future society?

Some form of gene manipulation is happening all about us today, making fruit seedless, causing them to grow to monsterous proportions, and crossing them with other fruit to make a more potent fruit of vegetable. It is happening with designer cats and hybrid dogs, you have here of a Cockapoo or a Schnoodle have you? At some point being able to control aspects of your unborn child will be possible. When that time come will it be more to the benefit to society by having kids less susceptible to being obese, ill, and learn quicker. Will society be more harmed because the “enhanced” people will be picked and chosen more then the “natural” people creating an unenhanced subclass?