It's definately not ethical, if not a slippery slope. (
Even the Catholic Church is against it - but that's a seperate debate for another thread for all you Curts and Perfections out there.

).
There has been one time in history where a nation even tried to genetically alter a region - although in a brute force way. Now, it can even be done subtly. Right now, if it's $70,000 for the "perfect baby", I don't think many people -- maybe except the rich -- will go for it.
Imagine these scenarios:
Scenario 1: Several of the wealthy elite, especially those with corporate interests, decide to form a family line of "intellectually business minded" children. Maybe not much to go on there, as genetically, their genes may naturally be passed anyway, but this ensures it 100%. Kind of an insurence policy to pass the family business along.
Scenario 2: The price comes down, and everyone's doing it. Now, You've got maybe, 80% of the population that are doctors, musicians, lawyers, scientists. Great, but then you're lacking manual labor. It'll be an economic change.
Scenario 3: The government regulates a defined set of genetic characteristic that a child can be. This may wind up creating many "twins" if the genetic code is specific enough that they're virtually the same. (or some computer program re-programs it that way) Put this in the hands of say, a communist govenment, and you may have a "Utopian's Dream", where a certain, predictable percentage of the population will have one interest over another.
Scenario 4: I'll just toss out a "nightmare scenario" for all of you. Although like #3, the government goes to the extreme. They create an intelligent class of people to be doctors, lawyers, scientists, and whatnot. Now, they also create a lower class of the gene pool where people actually have lower intelligence, and are very submissive (and naive). The only thing they have going for them is being resistent to the pain of manual labor. Their genes are also programmed that they do not sleep, so that they are forced to work 24/7. They could also completely remove people's gene that controls how religious or non-religous they are (yes, they actually found that gene).