Obito, the person, died as a kid when his word fell apart. It's very fitting that we got a moment like that. It really surprised me. I'm not loving the current arc, but I really am a fan of Obito and that moment was just so awesome.
Hopefully they can grow up together in the afterlife or Obito and Rin get to spend time as together as kids since the were both robbed of their innocence via either dying or all the messed up stuff Obito experienced or dished out.