The implementation of 'designer' babies is certainly a logical step in the evolution of the species. Being able to eliminate birth defects and potential diseases is a watershed moment in evolution. Because there are no human beings that are being harmed from this genetic selection process, I think that it's a perfectly fine alternative for parents who are having a child.
No one should have the right to create designer babies. That ban should apply to all: parents, doctors, governments and businesses. A baby is the embodiment of the miracle of human life. It should not be tampered with or destroyed because someone has determined that it is the 'wrong' sex or fails to meet other 'requirements'.
Designer babies should never be created. There's nothing wrong with the old fashioned way. Perhaps parents may not get the sex or eye color they hoped for, but designing their offspring seems too extreme and calculated. Plus, it wouldn't be fair for economically-challenged people who couldn't afford the process. Let's leave nature to nature.
The main ethical argument against designer babies is that it is another way for the wealthy to demonstrate their wealth by defining what is desirable in characteristics. Although this seems demure, the ultimate result might be a separation of races into a supreme and a sub-race, not unlike that Hitler tried to create.