yeah, i'm not sure how much of a NEW trend this is as much as maybe a recurring part of other larger trends that have been going on for the past decade, from rock-chic (you'll see karen o wearing them really often) to "boho" of the mid 00's to a lot of the general schoolboy/schoolgirl things a lot of designers do as well.
that said, i love fingerless gloves b/c i hate how restrictive gloves are... can't use my iphone, can't tie shoes, etc -- i frequently wear them UNDER mittens though since it's so cold here in NY. that way i can take a mitten off if i need to use my fingers, but without making the rest of my hand freeze too much....i actually started doing this back when i used to snowboard & would NEED my fingers to be adjust a binding/get my ski pass/fix my headphones/blow my nose/etc and taking my mitten off and exposing my whole hand/wrist would HURT... and it ended up transitioning quite well to regular winter wear, ha.
though in fall/spring i do just wear them because they look cool and for no glove purposes whatsoever... ha.