Yeah, as soon as they discovered water I thought this was a given. It's cool that they're still continuing to gather more data, though. My least favorite thing about science is that, even if we can prove that life once existed on Mars, we'll never be able to see it.
What I often wonder is this. If life did
exist on Mars at one point, how far did it evolve? Microbes? Plants? Did Mars have oceans full of crazy Martian fish? If we ever make it to Mars and establish long-term colonization there, will we one day discover the fossils of an ancient Martian dinosaur?