(Urgh, time ran out when editing the above. You really should stop the clock when someone clicks the edit button, El Reg.)
As for why mks, it seems there IS some natural coherence between the units, particularly when you mesh electrical phenomena to physical ones. In fact, this is why the kilogram was used versus the gram: the relationships didn't fit with the g but did with the kg. In fact, modern science notes a lot of interrelation between mass, energy, and time. That's one reason for the redefinitions. With the second defined as it will be, one can redefine the kilogram in terms of the Planck constant (which uses time), redefine the ampere in terms of the elementary charge (which uses time), and redefine the Kelvin in terms of the Boltzmann constant (which uses time, mass, and distance which is unchanged).
That sounds a bit suspect to me. In fact, reading into it a little bit, it seems a bit dodgy to me that a lot of science is based around arbitrary base-60 measurements of time. I can accept that the concept of the Planck constant (and what it represents) can be universal, but its value certainly can't be constant if it depends on the length of a second.
Oooh, is that a can of worms? How nice... ;)