Like an 80's skinny tie, it looks like Torpedo bats are back according to @Consultant. How they made their way from Japan to the US (where the sport originated from) is probably a great story that I'd eventually like to hear. I believe him, and I think this makes total sense as the Japanese and Koreans take their baseball very seriously.
With the Torpedo bats, there is a larger surface area and sweet spot to hit the ball. Wow, it is as simple as that. Golf clubs come in oversized heads as well as tennis rackets. In the case of tennis rackets its been 45+ years since the oversized Prince tennis racket came out when I was in high school. People laughed and scoffed at them at the time...calling them "butterfly nets" but they were deemed legal. Slowly people went from 85 sq in (and smaller) frames to newer 95 sq in frames in the 1990s. Today, I play with a Yonex 100 sq in frame which is fairly standard. Huge difference in the size of sweet spot. As we all know, baseball is a sport that is not conducive to change. Look how long it has taken MLB for the simplest of changes and modernization. Over the last decade, they've tinkered with defensive alignment, DH, extra innings, replay, etc... I find it so ironic that the simplest and latest thing (and I don't think it is hyperbole) is the equipment. Let's all welcome Major League Baseball to the 21st century!
As always, JMO.