Allow the designer to choose what kind of element belongs on the layer so that when assets are brought into the document they are automatically placed within the appropriate layer. For example, if the designer sets a layer to "Photography" then all raster-based imagery is automatically placed on that layer.

Other layer categories could be Type, Vector Art, Shapes (and by that I mean InDesign shapes), and more. Of course, once placed, the designer could then move elements to other layers as needed.

Additionally, if the document has already been created and elements have already been placed, then there could be an option to create the Smart Layers and then have the application analyze the document and move those existing elements to the corresponding layer.