It might have a few practical purposes, truthfully. Something hand-held that could cut pretty much any manufactured thing we made regardless of size? Someone would find a use :P

The issue I see is power and heat. Sure, even this nanobattery tech comes around, there's no way it could power something like this for more than a few minutes at a time. Plus, once you turned it off... these ceramics that have been hotter than the sun are now collapsed back inside the handle you're holding, roasting it and all it's components :P

Still... the most achievable design I've seen so far