If what is or is not an ethical truth is contingent on the types of biological organisms that we are, then changing the types of biological organisms that we are will change the nature of what is or is not ethical.So writes Greg Nirshberg in a reflection titled Genetic Modification and Human Ontology. This is probably useful as far as it goes.
One of the matters scarcely explored, however, is that significant modifications to the human genome and associated systems, will, if undertaken at all, be undertaken in the context of changes in even larger the systems in which they are embedded.  To (mis?)use the language suggested by Andrew Pickering, there will be a 'dance of agency' between (on the one hand) scientists and society and (on the other) the world as revealed through performance. Agency -- and therefore ethics -- will be an emergent property of interaction between the two.
But even if we are necessarily ignorant of many of ethical (and spiritual) questions that will confront us or our descendants can we not still develop working hypotheses (or ideas to explore in performance rather than cognition)? So, for example, we may consider this from James Lovelock, (echoing Lewis Thomas here):
The remaining life span of the biosphere is unlikely to be much more than 500 million years, so that if humans died out the chances of our replacement by another intelligent communicating species is improbable. If this is true then we have a goal a purpose. As part of the Earth system our job is to help keep our planet habitable and perhaps become a step in the evolution of an intelligent planet.One small but essential way of pursuing such a goal would be the tending of forests and other ecosystems through interaction and learning over time: techniques of ecological restoration/recreation/new-creation that are 'alive to emergence.'
 See also level 3 systems complexity as described by Brad Allenby and Dan Sarowitz in The Techno-human Condition, plus their short posts here.
(Image from Solaris - Lem/Tarkovsky)
P.S. 9 Feb: 'You...have to consider the possibility that cognitive enhancements may go hand in hand with moral enhancements.'