For those with mixed/homogenous monitor setups, it would be very nice if you could select independent sets of monitors to use "Span Image Across Monitors", and "Use a different image for each Monitor" for others.
For instance, I have 5 monitors: 3 1920x1200s in line across the bottom, and 2 1200x1600s above them. It would be nice if I could span an image across the 3 lower monitors, but have the upper 2 display different images. Or maybe have the 3 lower, and 2 upper both display different spanned images.
This is clearly a low priority request/suggestion. I just thought I'd send it your way before I forgot about it!