a fellow papervision3D enthusiast zeh (creator of the popular mctween) has created a new way of animating full 3D objects in the flash/flex environment with 100% code! introducing the caurina tweener, which is now hosted on googlecode, this re-envisioning of tweening is no longer a collection of h4x and prototypes extending existing ones. zeh has written full static classes following the idea of simple, one line commands. tweener is still in development, but is completely stable and functional.

check out the sound visualization demo i created using pv3d and tweener
http://lab.x-e.ro/spineSound/ (source)

UPDATE!

i have created a new version of the demo in flex using mxml. this demo also has the ability to dynamically change the colors of the filters applied to the spikey ball. i also compiled this demo with the current trunk version of papervision3D as well as the new 1.5 refactored branch to test the speed increase with the new version. 

check out the 0.91 version here (source)
and the new 1.5 version here (source)