the great thing about standards is that there are so many to choose from

I have a suspicion that, while I Want My Green Plug and their associated blog One Plug. One Planet want to replace all power adaptors with theirs, all that will really happen is that:

number_of_power_adaptor_variants = number_of_power_adaptor_variants + 1

I’m not wild about their idea for DC power strips. The I2R losses would be huge.
Also, dealing with the world of input voltages and frequencies, not to mention the many plug variants, would make the thing huge, heavy and expensive.
But the fact is, there’s already a standard low voltage power adaptor: the USB mini-B.