Here's my response to The Contrarian's article, "Buddhism vs Transhumanism."
Hey Casey, great post.
Regarding your statement, "Buddhism seeks to improve conditions not through transcendence, but rather acceptance," one must acknowledge the need to accept things when they are beyond our control.
Consequently, as compassionate Buddhists who are concerned about not just the suffering of all sentient life, but the optimization of subjective experience as well, we are motivated to work to find solutions that put as much control into our hands as possible. Buddhism does not imply passivity.
Also, transhumanism, as a form of applied science and technology, is an epistemological tool whose proponents seek to find the true nature (and alternate modes) of being and existence. That's also the goal of Buddhism -- the seeking of the true nature of reality.
And finally, one of my favourite Dalai Lama quotes (which I'm sure you've already read): "My Tibetan goals are the same as those of Western science: to serve humanity and to make better human beings."