|Scattering includes scatter %, count, and count jitter.
Texture means that you can paint with texture! Many are available to be loaded and you can make more of your own.
Dual Brush enables you to "marry" two different brush effects into one.
Noise lets you add noise to a brush stroke.
Wet Edges same as in PS 6.
Airbrush makes any brush into an airbrush. This means that when you hold the brush on the surface, more paint will continue to flow as long as you are holding it.
Smoothing claims that it is supposed to make your curves smoother. I couldn't get it to make mine smoother, though.
Protect Texture makes it so that when you are painting with a texture, you can keep the same texture for other brushes too.