Not to nitpick, but:
The article clearly states that Walmart will only sell "concentrated liquid detergents", it mentions nothing about powders.
Article goes on to state what many have known for ages, nonconcentrated liquid detergents are mostly water. So removing all that water saves bulk, weight,packaging and many other costs, in turn is good for the environment. What would be interesting is if product prices declined or remained the same given the above savings, and that the technology to concentrate liquids is not really that new.
L.