See the rocks in the bottom left of the picture that disappear? That's because they're chunks of ice that are evaporating now that they've been brought up to the surface, and exposed to sunlight.
Now we've known for some time that there's Ice on Mars - at the polar icecaps. What we haven't known is if there's ice stuck in the Martian Soil. And that's a Big Deal, because Ice in the soil means that Life could thrive on Mars.
Could it evolve there? There seems to be no reason why not, and if we don't find life within the Martian Soil or bedrock, that will tell us something too about the chances of finding life elsewhere. Because if it isn't found in such a relatively hospitable place, one periodically hit with Life's precursors just like the Earth is, then it means there's something else necessary we haven't thought of. And life will be rare in the Universe.
I think it now far more probable than not that Life, similar to some of the extremeophiles found on Earth, will be found on Mars. It will be astounding if Hypoliths or Endoliths aren't there somewhere. Of course, it might take us some time to find them.
In the short-term, colonising Mars with Earthlike life and giving us another planet is very probably feasible. The planet is rather small though. In the medium-term, it's not really a good bet, simply because the planet is too small to hold much of an atmosphere. It would require domes, or even a single cellular building covering the whole planetary surface, a la Trantor. In the long-term, by the time we are able to shift planets around and control gravity, we'll probably have outgrown the need for planets anyway. Or suns. Or corporeal existence. Assigned reading on the subject: The Last Question.
Photo courtesy of Wired.com via Little Green Footballs.