T-U,
Some part of the renderer have been made faster in some situations, yes. The GI lookup improvements should apply well to dense vegetation as far as my testing has shown. But in many scenes you may find there is no apparent speedup in the next update if you only have one core to run on. Karsten's benchmark actually runs slightly slower, for example, due to the way we had to fix some bugs and the improvements made to the ray tracer. Swings and roundabouts, as they say. The solutions to some rendering problems unfortunately result in things taking a little bit longer. Overall I think it will prove to be faster on complex scenes.
Matt