Natural Limitations - What, if anything, is the line

Our controversial debate this week will focus on the following questions: 

What, if anything, is the line that human beings should not cross in their attempt to transcend their natural limitations? In other words, how far should we pursue the goal of transhumanism? If all technology allows us to transcend some limitation, how far is too far? Biological implants? Artificial body parts? Genetic engineering? Mind uploading? Something else? If you think any of these is ethically too far, what is the difference between proposed technologies and current uses of technology to extend human abilities? Or if you think these proposed technologies are ethically acceptable, how do you respond to the worries others have? Be sure to discuss such relevant issues as the fundamental purpose of technology, whether technology is ethically neutral, how technology limits our freedom (see Ellul), etc