Ok, two features I just checked in that I'd like some feedback on.
1. If you're looking at the component side of the board, and the
component layer is the active layer, and the solder layer is
hidden, and you flip the board over... the solder layer is shown
and made active and the component layer is hidden. Same when you
flip back.
I.e. if you set it up so that it's like a real board, pcb will
attempt to preserve the illusion.
2. When multiple layers are visible, the non-active layer groups are
drawn in a slightly faded color.