Agreed, it makes it possible to take energy that is impractical to move from, say, an equatorial area, and convert it to hydrogen which might be easier to transport. I can imagine that tidal or geothermal energy could be employed to do this in offshore power plants.
I would imagine that due to the difficulty in moving hydrogen gas, it might be easier (certainly safer) to pump the salt water.
Except for one snag. With this pocess, you can not separate the hydrogen from the process of separation-ignition. The heat that disassociates the water molecules also ignites the hydrogen.
It takes far more heat (energy) to separate water than it does to ignite the hydrogen. This process isn't new except for the idea that this guy is using microwaves to pump enough energy into the water... far more that he will get from burning the hydrogen.
Eventually, this guy will fade away and at some point in the future, some will blame "big oil" for hushing his discovery.