Puting all the chamicals in our food and the weaker in the pack reproducing evolution aside. If we are talking about when scientists actually sit down and say " Well gentleman what is it that we should make ourselves like" then i think the concequences could be disasterous. All moral questions aside looking at it from a scientific perspective there is no reason why this could not work well when we develop the technology nessisary to evolve ourselves. However i envision given our curent human nature we will rush into this process without factoring in all the factors and end up with a biological disaster on our hands. Im not trying to be pesimistic but i thik the process of evolving ourselves is to complex for all the factors to really be calculated.