This is the first unambiguously good piece of news that I have heard in awhile.
What could be more interesting, more cheerful, more optimistic? It give us someplace to go if we decide to get up off our gravity well. It removes "earth like planets" from the realm of conjecture to hard fact, and gives us the possibility of companionship in the universe if only by proxy, standing in for all the other earth like planets that we will be sure to find. It might even give us a way to start triangulating how many earth like worlds we should expect to find. To me, it feels like a light at the top of the ladder, making the univers more awe-inspiring and giving it a more homey feeling all at the same time.
What a beautiful thing. I wonder if there will be any Gliesian stories in science fiction? Not that there needs to be. But I can see the romance of finding the first earth-like planet leading writers to claim it for its own.