This is a great topic with some very interesting thoughts from many people. I agree with most of what has been said so far. The one thing I'd like to add is, class, in addition to caste/race, is often under looked when analyzing inter-caste relationships and I have seen lots of cases where differences in upbringing and the economic standing of people have been bigger spoilers in a relationship than just differences of caste or race. And this appears to be true for both intra and inter caste marriages/long-term relationships. Just my thoughts.