If somebody ask you what is the most important part of life? what will be your answer? Respiration? Excretion? Reproduction? or what?  I would say Reproduction. Reproduction is the the only character why virus are considered as living things because virus can replicate by itself in host cell. 

The new synthetic bacteria can replicate itself in host cell. 

It has both positive and negative sides. Positive side: scientists can  develop vaccines and biological control mechanisms to control different diseases by utilizing this technology. Negative sides if the technology went to the terrorist it can be used to create the biological weapons. 

Anyway, we should look its positive sides now it has considered as a great landmark in the history of discoveries.