I read an article about the guys doing this a few months ago. They're trying to genetically engineer a pig that, instead of producing the 'normal' type of fat usually found in mammals, and swine specifically, they will store it as an Omega-3/6 acid, like Tuna. They're also trying to tinker with the nutrients and whatnot present in their bodies.
The result? HEALTHY PORK. That's right. Bacon that helps you loose weight. Carnitas that trim pounds and make you feel good.
Will they succeed? I have no clue.
I don't believe omega-3 fatty acids help you loose weight. how ever, the benefits of that particular fatty acid included increase IQ and decreased cardiovascular events. Many of the article have questionable statistics but that why your seeing "DHA enriched" or "contains omega-3-fatty acids" on so many foods.
As for the pigs, they did do it, unfortunately the sows no longer had the ability for muscle contractions and were unable to give birth. put a damper on the F1 generation. Now the goal is the engineer the gene to kick in after the litter is born.
As for the morality of this, no comment.
"If we knew what we were doing, it wouldn't be called Research." -A. Einstein