Scientists have found a planet that's not so terribly different from this one. Read the discovery.com article. It's about three Earths big, and is the right temperature to hold pools of liquid water. Astronomer Steven Vogt makes a point in the linked article that there's no reason to believe that there is not liquid water on the planet.
Statistically, it's being said that there might be lots and lots of planets like this, being that this one was found after "looking at just nine nearby stars." So if Earths are so common, maybe there are some cities full of quasi-people out there looking at our Earth in their telescope, just wondering. Hell, maybe some of them have visited us already. If the technology for such a feat is, in fact, possible (though I have no strong reason to believe that it is) then it's not outrageous to think that we've already been visited. I'm not going too far down that logical road, though, because I've seen where it can lead.
I only have one issue with the linked article, and that's the last line. I don't know if you can chalk it up to news sensationalism, or just an excited scientist speaking beyond the evidence (probably both). But, "It's pretty hard to stop life once you give it the right conditions," is a statement that is hard to back up. It may be true, but it really may not be true, as well. So far, we only have one example of life happening, and that's us and our family here on Earth. That statement sounds like a skateboarder saying that everyone has an innate talent for skateboarding, or a drug addict saying, "If you can get some crack, you're going to smoke it." Let's get a bigger sample before we start saying what's inevitable.
I'm excited about the discovery. I might be on a high percentile of excitedness, in fact. But let's not get carried away. The facts are exciting enough without an expert making guesses. Guesses that most people are going to take to heart, just because he's an expert. Like I've said before, an expert is not an authority figure, and no number of PhDs gives someone the power to change the truth.
I'm not saying the statement is false. I'm just saying we don't know if it's false. But what if it turns out to be true? Wouldn't that be something?