Basically, I believe that as soon as it is technologically feasible. Sex should be abolished and that incubation of new humans should take place outside of the body. This is working under the assumption that computers that are better than us are too difficult to build for a while.
In the interests of fairness lets consider some of the counter arguments:
1) Sex is enjoyable. The end aim should be happiness, lets not destroy this source of pleasure.
The act of sex is an arbitrary pleasure, if we have the power to eliminate gender we will have the power to create new and more intense arbitrary pleasures. Alternatively if you really love it that much, we can leave the act and become an asexual race that retains the act for the sake of tradition.
2) Don’t mess with nature. It will always go wrong in the end.
I have no patience for this argument. If this is true then we shouldn’t bother do anything even remotely technological. And anyway, isn’t the distinction between a beaver’s dam and a laptop arbitrary? Control of one’s physical environment is perfectly natural.
3) Sex is needed in order to maintain variation and may fulfill other important and unknown genetic roles.
Yeah, I don’t know about this one. But I see it as coming under the second point. I basically see this as a technological difficulty.
4) In order to achieve this on a large scale. Nazi style eugenics will have to be employed. This can only lead to tragedy.
This is the most serious and interesting criticism and can be made against all of my transhumanist agenda. A model for free market schemes must be put in place.
There are certainly other arguments against it. Please feel free to email your thoughts on the matter.