Funny thing you mention social intelligence. Today I've heard about studies how there are 3 things that interact about relationship (like 3 things to have a good relationship) and those are attachment (being close to someone that you miss him a lot and vice versa), caring (...well, caring) and sex. So when there are those three combined within both people it's a good sign. However the most important thing seems to be caring. I know it can sound like a ton of bullshit science behind a relationship, but just sayin' some informative
As for the business industry (if we're talking about emotional intelligence) I think it's very crucial and that opinion is not based on my todays readings. I think it's vital to have high EQ if you want to be a leader (in any aspect) or to run your own business. Being able to understand people better and lead them through emotions can be relatively easy and effective. There are also studies that show how people with high IQ (only) can and usually do achieve a lot less in life (speaking of course about business aspect). Picking people with relatively high IQ also means dropping and ignoring a lot of people with high EQ (as those who posses both are kinda.. rare).
It might be a 'new science' but I think it's a deep psychology when it comes to that subject. What I find interesting is that I think having the understanding of emotions and people and make you manipulate people. It doesn't have to be in a bad way, but it's like you're always one step ahead of them.