I'm not sure where to go with this, the concept provides more fodder for discussion than I can do justice.
What flavor of morality are we talking about? It doesn't sound very neighborly. In a nutshell, Mautner says that seeding the universe can be accomplished through a process of "directed panspermia". (Panspermia, what a great word, I should change my blog name) Specialized spacecraft containing bacteria and simple multicellular organisms would be sent to specific potentially fertile planets. In the words of Bill Cosby's Noah - "RIGHT!"
It's not that I don't believe that it could be accomplished. I'm sure it could, but should it be? This smacks of cultural superiority. My tribe-culture-nation is the most spectacular gift to humankind, therefore we will spread to every corner, at whatever the cost. I hope you can see where this is going. 100 people were asked, "Name a culture that was destroyed due to another culture's 'Manifest Destiny'?" The top ten answers are on the board. Survey says!
Actually why don't we send our bacteria out into the universe, maybe even some freeze dried embryos. I'm sure that the life forms on the destination planets would appreciate some snacks from space.