Ooooooh... good to know. Kovu did something like this a while ago, and it's basically wrapping around the features from GL Lighting into a minecraft entity, which is why they're limited to 10 or so lights, but then they look super cool, update dynamically, etc.
One of the limitations being: they go through walls
I didn't look super closely, and just assumed it was solving all of the problems with magic. Bummer.