Bull! That is probably the most unlikely turn of events. Here's why...
In order to survive and thrive, intelligent organisms must make their way to the top of the food chain - intelligence requires a much higher amount of food. That is why cows eat grass - and then we eat the cows. The higher energy needs of intellect means the organism is almost certain to be a predator.
In addition, in order to get to the top and stay there requires fighting for survival and winning. And that means the predator is most apt to be a predatory warrior.
Aliens from another world would most certainly be at the top of their known food chain, and war-like. So, if we ever face them, while they may make an attempt to be somewhat peaceful, it would only be for serving their purpose - they would not be interested in our purposes. As soon as we stop serving their purpose, you can bet they will make war against us.
Look at the history of Earth's nations - every time a superior race encountered an inferior one, the inferior one ended up pretty much extinct. Think Cortez and the Aztecs and Maya, or even closer to home - what happened to the great Native American tribes of North America. Even the aborigines of Australia and South America - they either assimilated into the superior society or they perished. Every time.
Don't expect any different from a superior race from another world.