In my opinion, evolution on our own planet is a great model for what we would expect for life elsewhere. More specifically, convergent evolution holds the evidence we need.
For example, eyes evolved independently in several different lineages. We would also expect life on other planets to have eyes. Wings also evolved in several different lineages, from insects to huge flying reptiles. It doesn't matter if you have 6 legs and an exoskeleton or 4 legs and an internal skeleton, wings are advantageous, as are eyes.
At the same time, these features require a nervous system, a way of coordinating sensory input and the firing of the musclature, at least for multicelluar organisms (there are single celled organisms with "eyes"). We can also see that intelligence has also evolved independently in several lineages. A great example is cephalopods. The ancestor of molluscs probably did not have a complex set of ganglia, or anything approaching what you would consider intelligentce. However, cuttlefish are relatively intelligent predators that communicate with each other through a language of colors expressed by their chromatophores. They have a rather well developed central ganglia and nervous system. The only thing really holding them back is the lack of myelin sheaths around their axons.
So why did our lineage, including our ape cousins and even our more distantly related primate cousins, become so intelligent? I think it comes down to our ability to use tools, to manipulate the environment around us. Other lineages lack this ability. Cetaceans can not grab rocks and use them to bang open molluscs that they would otherwise not be able to get to. Having hands makes all of the difference, IMHO. Without hands any further increase in intelligence can not be used.
If an ape level of intelligence were to evolve on another planet I believe that this lineage would need something like our hands. Hands allow us to develop technologies. An increase in intelligence allowing us to communicate these technologies to further generations will also be selected for. Even in chimp groups we see one generation teaching tool use to the next generation. What we see in such lineages is a selection of learned behavior instead of instinctual behavior. This is also a very important step, IMHO.
On a more philosophical note, we still don't know if a human level of intelligence is a good adaptation in the long run. We have built technology that is capable of wiping out our entire species. For all we know, this type of evolved intelligence is a dead end. Perhaps it self desctructs more often thant it doesn't. Human like intelligence may be a candle that burns very bright for a very brief time on the scale of evolutionary time lines. What we may find on other planets is archaeological evidence for cultures that reached our level of technology and then disappeared soon afterwards.
Or maybey everything will work out just fine and we will all have flying cars within the next decade!!! I NEED FLYING CARS!! WHY CAN'T THEY GIVE ME FLYING CARS!!! hehehe