Do you want to be able to create and save custom appearances in PV360? Well until we get this enhancement into a future release, is it worth $995 bucks right now to have it? If so, go and buy yourself a copy of Modo 401 and you can Create, tweak, and save custom appearances for PV360 to your heart's content.
Below is a SW/PV blue plastic material that I opened into Modo and added a few more channels (layers) to including a noise layer for the disfuse color to give it pink blotches as well as a noise layer that I assigned to bump to give it a custom rough texture (see below.) Now the only draw back is that in 360, you don't get a thumbnail, in 360 2010 beta you get a teapot object with the material on it.
From a workflow standpoint, it's not as good as having customization and saveability right in 360, but what's pretty cool, is that once the appearance is saved as a preset in the <pv360 install>\resrc\presets\materials folder, you can have Modo and 360 open and modify the appearance in Modo and reapply it in 360 without having to close either. I've included the custom appearance for your reference.
Oh, and by the way, this is strictly unsupported by us or Lux