Needs latest yafray, you can get it from cvs, but I have also binaries
for os x here:
http://www.coala.uniovi.es/~jandro/noname/downloads/yafray-0.0.6-3.pkg.zip
To use it, go to yafray panels (global settings) and uncheck the "xml" button.
That would tell the export code to avoid xml export and use the yafray plugin
instead. You'll see the render being draw while running and you can even stop it
with ESC key.
Since I'm sure problems will appear, expect updates soon.
Remember: does not work on win32
