The Doctor's smile went a little sad, but he understood.
They had likely been parted. And she was feeling that same desperation he had felt upon regeneration. He felt no terror in saying those words here, not as he had so often during the dreams.
Here he wasn't alone in any sense of the word. Here the guilt didn't weigh on him.
Here they had a chance.
"I love you, Rose Tyler. More than you might ever know."