Personally I think it would be great if humans started treating other humans categorically in an ethical way.
That's a ways off I'm afraid though. It's important to see that these are obviously non-related issues but I don't have much hopes for our stance towards Dolphins as long as we haven't learned to do this with each other.
To me this is quite obviously a very related issue.
As long as people refuse to recognize the moral interests of animals, it is not logically consistent for them to respect moral obligations to other humans. The moral distinction between animals and humans is a completely arbitrary prejudice and should be immediately identified as such by anybody with even a basic understanding of evolutionary biology.
That's a ways off I'm afraid though. It's important to see that these are obviously non-related issues but I don't have much hopes for our stance towards Dolphins as long as we haven't learned to do this with each other.