There's a fascinating (and at times quite acrimonious) debate on this and related issues between Stephen J Gould of Harvard University, and Simon Conway Morris of Cambridge University.
Gould argues that we arose completely by chance and that "if the tape of life were replayed" intelligence would not necessarily have arisen, because evolution is so random and easily influenced by minute events (i.e. the butterfly effect).
Conway Morris says that Gould is completely wrong and points to convergent evolution. This is the independent evolution of the same traits in completely separate lineages (for example, flight in insects, bats, pterosaurs and birds). He uses this (and quite a few other examples) to suggest that intelligence is a natural endpoint of evolution.
This debate is still ongoing and nobody really knows the answer. As with all endmember views, the answer probably lies somewhere in the middle.
Would life have evolved on another planet? That depends on how similar you think alien life has to be to that on planet Earth. I've been reading a little about the subject recently and it basically comes down to how you define life.