Woody: Why did they cancel the show?
Stinky Pete: Two words. Sput Nik. Once the astronauts went up, kids just wanted to play with space toys.
(Toy Story 2)
Space.com: NASA Researchers Claim Evidence of Present Life on Mars
I always get excited every time some mentions life (or the possibility of life) on Mars. Even if it is only microbial life, it still raises the possibility that life is not unique to the Earth, and I think proof of life will be one of those events that will change the way that we think about the universe.
And yet at the same time, I don't think the human race is ready for this piece of knowledge. It is good that our technology prohibits us from being able to reach out across the cosmos and exploit Mars' resources, because if we could, we would. Within a couple hundred years, we might have the technology to be able to colonize and land on Mars. With the possibility of life present, Mars is not going to be something that you want to change or terraform -- if Martian life exists, it should be given a chance to live and to thrive and develop. Just as we attempt to preserve endangered species here on Earth, we should preserve life on Mars. The problem with our efforts on Earth, is that we've done a poor job. If it's not warm-blooded, cute and furry, we haven't done well preserving them. With Martian life being microbial, i very much doubt that people are going to have the warm fuzzies when it comes to protecting to microscopic organisms (given that Earthlings have always associated microscopic organisms with diseases).
On the upside, it's tremendously hard to kill off a microbial species. It's a lot easier to kill the big, cuddly, furry things.