There is almost certainly life other than here on earth. How advanced it is remains to be seen.
From a scientific standpoint:
Complex organic molecules appear to be common. Just in the local solar system, moons of Jupiter and Saturn have these in abundance. So far all that have been discovered are carbon based molecules. While silicon based molecules are technically possible, they don't appear to form spontaneously as carbon based ones do in the right situations. Also, silicon is far less abundant than carbon in the universe as a whole. (Carbon is produced in large quantities in the hearts of massive stars then distributed when these stars die and go supernova.) For proper interaction of the molecules it's necessary to have a liquid suspension. Liquid methane is very common and can exist in the cold temperatures that are common in most of space, but water is actually one of the most common molecules, though it's restricted to a very limited temperature range as a liquid. Through necessity and sheer availability it is likely that most life is carbon based and in an environment where liquid water is in generous quantities.
As far as intelligence, it has evolved independently several times even among the currently existing animals here on earth (and who knows how intelligent some of the extinct species might have been.) One of the most significant evolutionary steps in the determination of the way life looks on earth is the development of the tetrapods (four limbed animals.) All land dwelling vertebrates (amphibians, reptiles, birds, mammals and even dinosaurs) are tetrapods. Just among the mammals you have primates, dogs and bears, elephants, and whales as highly intelligent animals with dramatically different evolutionary paths. Among the non-tetrapods the octopi are probably the most intelligent, and some species appear as smart as some monkeys. So there is a high probability of independent development of intelligence anywhere there is life.
From a religions (OK, Christian) standpoint:
At one point it was considered heresy to claim the earth was not the center of the universe. The problem with this logic is that it seemed to elevate man to not just the most important thing in the universe, but also to claim that man was more important than God. A more appropriate claim would be that God was the center of the universe with everything revolving around Him. With this is mind, it would be extremely arrogant to assume that God was incapable or unwilling of creating intelligent life other than that which is here. Are we alone in the universe? No, God is here. Is there other intelligent life? That is His choice to make, not ours.