But why is there no question of human biological reaction to said possible microbial life on Mars? I can't say I think the only thing to consider is whether there is water, and supported life, but also what the consequences of introducing any possible Martian life forms to our ecosystem (no matter how safe we would be, it could happen) might be...or ours to theirs(Imagine the lack of egocentrism it'd take!).
It all sounds slightly uncalculated. Like any new discovery, I imagine "we" may end up being too excited to deal with it smartly.