When I select wide wallpaper from Desktop Wallpaper Preferences and set Style to
Fill screen the wallpaper gets scretched and the content looks distorted. I
propose that instead of blind scaling the image could be cropped while aspect
ratio is kept. In case of wider-than-screen image this would mean that height of
the resulting bitmap is same as screen height and the area near the left and
right edge is cropped away.

In other words behavior would be similar to "Scaled" style but instead of
margins in top and bottom part of the image in left and right is left out of the
screen.