Your comment about aggression being bad seemed off to me. Aggression is a useful strategy. Maybe you meant irrational misplaced aggression...
Gender is pretty useless. I see no reason that we would opt to keep it around once we have control of our bodies. Assuming that everyone gets one body and it's rather permanent (which is a pretty big assumption), either we all figure out what the optimal physiology is and converge to that, or we decide that we like diversity or something and invent vast hordes of unique bodies, or some mix of both. I see no reason to keep a binary (which we don't exactly have in any case). Analogies can be drawn to fashion; there would likely be popular mainstream body characteristics, and vast numbers of subcultural variations.
I think you are vastly underestimating the reach of transhumanism, given that 'it occurs'.
Edit: Natural selection hasn't substantially applied to much of anything for the last few thousand years, and will be totally thrown out when we get access to our source code. Evolution is in our origin but not in our future.
Natural selection hasn't substantially applied to much of anything for the last few thousand years
The apparent position of the sun in Earth's sky hasn't substantially changed in the last few seconds.
Upon reading Eliezer's possible gender dystopias ([catgirls](http://lesswrong.com/lw/xt/interpersonal_entanglement/), and [verthandi](http://lesswrong.com/lw/xu/failed_utopia_42/) and the other LW comments and posts on the subject of future gender relations, I came to a rather different conclusion than the ones I've seen espoused here. After searching around the internet a bit, I discovered that my ideas tend to fall under the general category of "postgenderism", and I am wondering what my fellow LessWrongians think of it.
This can generally be broken down to the following claims:
EDIT- Due to some really insightful comments;
I replaced men being prone to aggression as a negative, with men being prone to suicide.
I made the verbiage a little more explicit that no one would be *forced* to change, but would seek out the changes that transhumanism would have available.