i am still searching for some papers for fast soft raytraced shadows. i found two.
could this be in the future in poser?  bagginsbill you are the expert. what do you think? could this work with firefly?
artis.inrialpes.fr/Publications/2005/LAALA05/SoftShadowVolumesRT.pdf
www.tabellion.org/et/paper07/egsr07_mtsm.pdf

faster shadows are always good right he he :)