Are lights using Altivec?

I logged onto SL for the first time today. Framerate was pretty bad on my computer, but that is to be expected from a beta. Still, I was wondering what the main cause was for it running so slowly. Someone mentioned that since SL has so many different lights going, and because most graphics boards don’t have sufficient lighting effects for SL, the lighting part of the graphics process is processor bound. So naturally, I want to know if Altivec, the best SIMD architecture to date, was being used to speed things up or not. It seems an awful waste of FPS if it isn’t.

Also, I’d like to know about other SL bottlenecks, if we could discuss that.

On Mac, SL's in Alpha.