You can use Inkscape scripts like this one to export directly to a 1 px : 1 mil dimensioned footprint in gEDA PCB format, which KiCad can load easily enough:
The chief advantage of converting beziers and cubic splines to line segments is that line elements are supported by DRC in KiCad.
If there is demand, I could create an additional script for export to a KiCad native format.
pcb-rnd and gEDA PCB support arcs on copper, but until KiCad does, conversion to bi-arcs would not make a lot of sense for copper layers.
There are other workflows too, that have been described before: