The damned thing has been replicated by teams in China and Germany, and both teams say they saw otherwise unaccountable thrust.
That's apparently enough to get funding to actually test it in orbit, likely by three independent groups:
So relatively shortly (a couple three years) we'll know whether it's real or just another pipe dream.
Me, I *want* it to be real, but I won't hold my breath.
Mark L. Fergerson