This, and the discussion of "per," seem to me to favor non-technical word usage. That Michigan radio article is pretty interesting, but if a physicist had been invited to the discussion, he would have preferred "per" because all the best units have "per" in them:
miles per gallon,
cycles per second (older term for Hertz),
coulombs per second,
per se (sometimes written per say),
and the old college favorite that makes fun of units,
furlongs per fortnight.

Speed is motion per unit time. Velocity is motion per unit time in a particular direction, that is, it's a vector while speed is a scalar. So, yeah, most people don't use "velocity" correctly. Now that I think about it, any motion not in a straight line can't have velocity unless, maybe, there's some formula attached to the number that defines how the moving object deviates from straight line motion.