M_L_R: I've been running Snow Leopard with P8 since it's release with no problem so far. IDL runs smoothly and opening Poser files as old as P4 do so and render without a hitch. P8 DOES (oops, sorry, Bagginsbill) does feast on my Core 2 Duo processor when rendering with IDL, but I wouldn't open a browser during a P8 (or Bryce for that matter) render--as I wouldn't do so while burning a DVD--if I want either to be problem free.

I do have a issue with Bryce 6.1 freezing while trying to load textures from an imported P8 obj under Snow Leopard, but that a whole 'nother forum.