To address some points from several posts:
No, there really are discussions on the ethics of microbial extinction, for example through disease eradication. We are making life extinct through our medicine system, you know.
Almost all of our food is genetically altered by selective farming or breeding. The agricultural revolution we had 10,000 years ago was us, for good or worse, meddling with the order of things. Whether all that genetic manipulation happened directly or indirectly isn't very relevant to the risk argument: we have made species extinct and permanently altered life and weather in the planet by way of our agricultural interventions during the past millenia; societies have conquered others due to superior plant genes, and diseases were used to destroy major civilisations. Entire ecosystems collapsed because of our ancestors, and a bunch of new diseases appeared because of our selective breeding and farming.
Risks have to be weighted according to specific ethical theories, not opinion. For policy making utilitarianism is preferred. While risks and damage of GE are high, the risk and damage of social collapse or humanity's extinction is much higher; so when put in a balance the benefits outweigh the damage, depending on which ethicist is making the calculus. More people could benefit from genetic engineering than without it.
The problem is that as it is and with our current tech the planet cannot sustain humanity's growth, and also that accessible genetic engineering is inevitable (for terrorists too). We won't be able to stop wars, terrorists, or forcibly control fertility. Genetic engineering has the potential of giving our species some extra centuries to live. And
Someone is certainly going to do it, it's best if we do it too, since not all scientific superpowers are peaceful and friendly.
And this discussion is a very old cliche of our Western culture, it appears in many forms throughout history - humans eating from the tree of knowledge in christianism, prometheus teaching us how to make fire (humanity should not have such power, say the gods), etc.
All technicalities aside though, who wouldn't want more babies like this pomato tree here?
Massa wrote:You won't shape life.
What about craig venter?