With 13.1, there are very few changes. The pointer Auto-Hide setting does nothing - whether it is on or off and whatever time setting when on, the pointer disappears in 10 seconds. After about 30 seconds of inactivity, you still need to click the mouse to get it to work. I am using an Apple Mighty mouse (bluetooth) and the scroll wheel works but can't be set to the more conventional scroll direction.
I have set the second mouse button to Dock since it is the only way I can get the dock to appear. Dragging from the bottom doesn't work. I tried setting button 2 to long press, but this is ridiculous - it literally does a long press, which slows things down.
It is frustrating that decent mouse support is almost there, but not quite.