Hi James,
It’s probably of not much practical use but FWIW:
http://news2.mcneel.com/scripts/dnewsweb.exe?cmd=article&group=rhino&item=367276&utag=
TL;DR
I wrote a script (left in alpha stage) to export svg files. In addition there is an option to auto-run the svg through inkscape and let that convert it into a pdf. The resulting pdf-curves are as smooth as expected. Be it that I know of at least one bug where higher degree curves were incorrectly exported.
-Willem