I'm betting we're no more than a decade away from fairly advanced (if also damn creepy) sexbots/chatbots. I'm also guessing that as the chatbot programming gets better, there will be people who honestly fall in love with these things - admittedly, they will almost exclusively very sad and social awkward people.

Of course, 15+ years after that, I'm betting that we may start seeing the first actual AIs, which makes the question of human robot love far more complex.