Projected drop shadows as an option.
Please consider adding a projected drop shadow as an option to the drop shadow effect. See attachment for a visual.
It's funny because Illustrator already has similar, but far more advanced technology in its 3D Extrude and Bevel effect, but lacks the capability to produce this far more commonly used effect.
In fact, I imagine just a checkbox in the Extrude and Bevel effect panel to lock the angle/rotation of the starting object would be a simple and satisfactory way to incorporate this feature.
Great idea Jeremy! In real life, objects rarely hover above a surface. Shadows are attached to the object casting the shadow.