I think it is unlikely that at this time, there is any other form of intelligent life in the universe, or at least any form of life which we as humans can comprehend.

While I accept that we have only sampled a tiny fraction of the Universe this is not simply a matter of humans finding intelligent life. For life to be considered intelligent I believe it must have several things.

1) Life form that are to be considered intelligent must be self aware.

2) They must have a form of language or communication. This is essential for the formation of any kind of social structure, inter species cohesion and technical advancement.

3) They must be able to recognise intelligent life themselves.

Taking these premises (which I admit is an assumption and they may well be debatable) and what we know about the universe, we can deduce several things.

Firstly, that these beings must be evolutionary. Unless we make the assumption that they pre-existed the universe or have the ability to move beyond it (which would make us question why they haven't found us yet anyway), then we must assume that they have evolved from simpler creatures, which roughly fits the model we have on earth, of creatures becoming more complex at an exponential rate, with maximum intelligence matching that complexity.

The problem this provides is that if these beings are evolving in much the same ways we are, and developing intelligence in much the same way, then the odds of them being at an evolutionary stage at which they could be described as intelligent (humans have been at this stage for maybe 100'000 years, possibly more if you count other primates) The odds of them occupying a similar time frame are relatively low decreasing the probability that they are actually out there. Were they in some way more advanced then us it seems logical given the rate of human scientific progress and data storage that they would have discovered us by now, unless of course they have already become wiped out in which case they are no longer out there.

The fact that no-one has discovered us suggests that there are no species within the universe that have much greater intelligence than us, and if not then are unlikely to be species who are less given species who are more intelligent would have lasted longer than species who were less hence making their probability of existence higher.

Just some thoughts.