Some recent articles on creating artificial life:

Researchers build huge DNA chains.
"Scientists believe they will be able to create synthetic lifeforms within the next decade.
"That is the confident prediction of researchers at the University of Texas who have managed to assemble very long strands of the life molecule, DNA, in the laboratory."
http://news.bbc.co.uk/hi/english/sci/tech/newsid_620000/620847.stm

Scientists call for life creation debate
http://news.bbc.co.uk/hi/english/sci/tech/newsid_556000/556984.stm

One could imagine creating such life forms that could explore other planetary systems and send back information on those systems.
Would it be ethical to introduce life to those new planets as a means to terraforming them? Suppose we wanted new planets to colonize, at what stage of development would we allow there to already be life on that planet? At the microbial level? At the invertebrate level?
One would presume we would not introduce new life if there is already intelligent life on the planet, but what about earlier stages that we could imagine would likely evolve to intelligent life?

Bob Clark