With hundreds of known exoplanets it is pretty obvious that planets are a natural byproduct of star formation. Researchers are finding out that planets can form in very extreme environments.
Astronomers have discovered planets orbiting a double star system as depicted above - http://science.nasa.gov/science-news/science-at-nasa/2012/12sep_weirdplanets/.
What's more, planets have been discovered for the first time in a star cluster http://www.jpl.nasa.gov/news/news.php?release=2012-289.
I have no doubt that there are BILLIONS if not TRILLIONS of planets in our Milky Way Galaxy. Every star could have multiple planets....look at our own Sun and the solar system it spawned.
The follow on to this plethora of planets is that life has plenty of places to start and evolve. This too I believe - life, including intelligent life, abounds in the Milky Way and Universe.
Remember, there are BILLIONS of galaxies out there and they all are teeming with planets and life as well.
I think that Einstein is right about the speed of light and if so, it will be very, very difficult to soar amongst the stars and visit these planets as we see in Star Trek.
Perhaps we will one day intercept the radio calling card of an alien civilization and know conclusively that we are not alone.
Sky Guy in VA