Since we're all conjecturing anyways...
Oooh, I want to play.
Perhaps there are intelligent entities out there who will interact with 'us' after we assemble ourselves into a higher form of life, just as we have been assembled from lower forms of life.
Flying around the planet for a business meeting would seem pretty outrageous to a single celled organism. On interstellar scales, we are the single celled organisms.
We're going to have to successfully grow our population to levels that boggle the mind before we become significant, and even then, we're going to have as much chance to interact with aliens in their own environment as a human white blood cell has of chatting up a cell from a dogs liver. We're going to be structural components in such a scenario, so most of us will exist our whole lives "inside" the "body", except those that are born to be "skin".
Going further, the intelligences involved would have concerns as far removed from our own that we wouldn't have any chance of recognizing them. Their lifespans would be vastly beyond our own, the way our own lifespan is vastly greater than a skin cell.
When you get right down to it, it's entirely possible this is already going on. How the hell would we recognize such a thing?