If you really think about the potential humans can actually reach, its only being hindered by our limitations. If you want to push those boundaries by genetically making us better, I'm all for it. I mean who wouldn't want to see Albert Einstein compete in the Olympics. I know I would.
I think we do need to be genetically modified to reach a more evolved level. The environment isn't putting pressure on us anymore like natural selection did. Perhaps the way we live now will cause us change, but what we really need are larger prefrontal lobes and smaller adrenal glands.
While it seems that human genetic modification is the direction we are currently headed towards and while it seems in my eyes that we will in fact be doing a lot of human genetic modifications, it is my belief that going down that path will lead to the end of humanity. When you start messing with nature bad things happen.
Humans don't outright need to be genetically modified to achieve a higher, more evolved level. The process would happen naturally over the course of x-amount of centuries/millenia.
However if we want to drastically cut down the time for human evolution to occur, then genetic modification is probably the best way we could do it.
Human beings know very little about the mystery and sacredness of the genome. Humans have already proven incapable of properly handling the genetic modification of plants, like Monsanto's round-up ready crops, which have spread into organic and wild plant communities causing all sorts of deformities and other problems. The unintended consequences of human genetic modification could radically damage life as we know it, and that is not a risk worth taking. The best avenue toward human "evolution" is expansion of consciousness through love, compassion and creativity, not fiddling around with dangerous genetic forces we do not fully understand.
While being genetically modified could serious speed up the process of evolution. You can never take into account how much more precise natural evolution is compared to genetically enhanced evolution. The way the environment slowly changes around us, our structural frames adapt for those changes the same way. Things that we can not see and would not know to look for.