I'm not buying it. The lower round-trip efficiency of hydrogen means you only use it where batteries can't do the job (chemicals, air/sea travel, long-term grid storage). Batteries and hydrogen might both be competitive in certain niches (long-haul trucking, short-haul air/water, some train routes). As batteries continue to improve, they will actually cut into the addressable market for hydrogen, at least in mobility (chemicals and long-term storage are safe though).