It's getting more and more likely that we're not the only life in the solar system. Hydrogen-breathing, acetylene-eating, methane-pooping microbes on Titan! It's a big maybe, but my god it's beautiful.
Between this, the ease with which life could evolve on Europa given the conditions we know exist there, and the increasingly strong evidence that there may have once been or may even currently be microbial life on Mars, it's a damn near certainty in my mind.
Life may have evolved independently as many as four times just in our solar system alone. That's not even including the entire rest of the universe.
Makes me happy, is all.