I've been watching the heroic efforts of the STS-125 to revive the Hubble Space Telescope almost non-stop. There is a neverending debate between those who wish to see the continuation of human spaceflight and those who argue for robotic missions. For a time, some in NASA wanted to send a robotic mission to Hubble. Anyone who watched the repair could see that it was far beyond the ability of any current robotics, but the robotics folks simply say that's because Hubble was designed for humans and not robots. This fails to account for the repairs done to systems that were never intended to be serviced on orbit. I think these guys definitively proved the advantage of keeping humans in the loop.