However, I do think there are enough scientists out that that believe there are other planets just as "special" as Earth. As Jodie Foster's character pointed out in the movie "Contact," the Universe is an awfully big place and it would be a waste if life was only found on Earth.

Keep in mind that humans will have to leave Earth at some point (assuming we don't destroy it first) because in approximately 50 million years our Sun will grow large enough to consume Mercury, Venus, and maybe Earth before it shrinks to become a white dwarf star. If humans survive the Sun dying and are still on Earth, then they get to look forward to the Milky Way Galaxy and Andromeda Galaxy colliding with each other in approximately 40-50 billion years.