If we all get up tomorrow morning and hear that an advanced alien race has contacted the President what would that mean for humanity?

Would it encourage humanity to work together? I know most of us would be both excited and frighten. I would not trust any alien species until they proved themselves. Would you? Any species that could reach Earth from another part of the Universe would have Technology beyond anything we will have for decades. Would this change everything here on Earth? Would our Wars come to an end?
Do you think this will happen in the next decade, sooner or never?