A small quote from the article:-
"We can study them now, we know where they are," says Sasselov. "We can find those that we would call habitable, meaning that they have conditions similar to the conditions we have experience here on Earth."
Sasselov goes on to suggest that if we extrapolate the data gathered so far by Kepler, the Milky Way could contain up to 100 million habitable planets.
Read the other two threads on this subject on this Board and follow the URL's that discuss this and you will see that the uncertainty in these early speculations and the conditions for life suggest that these type of estimates are very uncertain and , In my opinion, highly unlikely.
Stars have to be of a certain size to ensure a long enough life to allow Intelligent life to form. Their temperature must be in a certain range and they must have a stable amount of energy production. Planets must be in stable orbits at the right distance After that there are many other conditions for life to develop and the rocky planets must be inner planets with no massive inner giant or else planets won't accrete out of chunks at all. Then there is the matter of water. Ammonia atmospheres probably wont hack it as a life supporter.
If there are 100 million such planets then we can expect there to be life in the Galaxy other than our own. If there are 1 or 2 then the issue is in much greater doubt. Time will tell as we can enumerate and measure conditions for life in the future--stay tuned.
The thing that should be noted about Dimitar Sasselov's comments are that either way, all the Kepler data so far is based on only the first 43 days of data. So even if the Kepler team has lots of Earth-Size planets, they will be orbiting very close to their parent star. From 43 days of data, having to make 3 passes to confirm the planet, the maximum orbit for any of the planets can only be about 14 days. That will mean they might be Earth-sized, but they will be baking hot.
Big difference between Earth-Sized and Earth-Like.
Sasselov tries to dispel the "confusion" over Earth-sized planetary candidates in a posting to NASA's Kepler mission blog. During his 18-minute TEDGlobal talk, "the expected number of planets, size and Earth-like chemistry got confused, and created a misunderstanding," he said. Read it here!
But things do look very optimistic for when they have results from several months or years of data.