That's painfully obvious.

There are several million abortions a year in this country and many more in the rest of the world.

I've discovered this morning that abortion statistics are not exactly easy to wade through. However, "several million" is a bit of a stretch. This CDC report (latest data, 2000) indicates a peak of 1.43 million in 1990, and a gradual reduction to 0.86 million in 2000. (Table 1, pp. 14-16)

A good deal of these procedures are carried out because the fetus is abnormal in some way.

Again, depending on who's displaying the stats, that ranges from 1 % to 3.3 % (Please note: I have not filtered sources based on their organizations' positions on the abortion issue).

Back of the envelope: Split the difference and say 2 % of abortions result from fetal abnormalities (detected in utero, of course); from the CDC report (Fig. 1, p. 12), a ratio of 250 abortions per 1000 live births (1996) implies a ratio of 5 abortions per 1000 live births for that specific cause. Is that a trend?

It's only a small leap from allowing parents to terminate defective offspring or those of the "wrong" sex to allowing them to custom order desirable traits for their children.

It is a leap of faith; small, perhaps, for such as are already poised on the precipice, itching to jump. For the realistic view of the science, Tom has already said it best.

. . . it will be up to parents to decide for themselves if they want their children to be specially designed or a throw of the dice.

Which, as I suspected you had, completely ignores the economic factor. If specific corrective measures are ever approved for human use, they will be prohibitively expensive; i.e., they will be yet another highly-visible perquisite of the super-rich, unobtainable for the common population. I refer you again to considerations of the potential backlash in my previous post (see also, K.S. Robinson's Mars trilogy for an analogous situation regarding "longevity treatments").

As for your view that "enhanced" people will want to do away with "unenhanced" people as a means of keeping undesired traits out of their gene pool, I don't buy it.

Really? Then why do you sell it, a mere four sentences later?

In fact, once gene modification advances past a certain point, forced speciation will likely be enacted to help insure unviable offspring aren't conceived on a regular bases due to the genetic incompatibility of the parents. [emphasis added]