It is less common to see computers which use non-USB wired keyboard, and mouse, but some banks, and offices still seem to use PS/2 keyboards, and mouses instead of USB wired keyboard and mouses.
They are going the way of the VHS. To be honest though I never saw the point of combining the two ports into one slot.
I think combining 2 ports into 1 slot save money for the PC maker, but make it frustrating for people who needs 2 ports, and dont want to use an adapter.
I always figured they came out with a keyboard and mouse which the wires for them both combine into one.
we still have mouse ball in-use in my friends house, he said it's much tougher than the new ones...