Frequent tipster Danny Korem calls our attention to the Merge Layers tool, which is a new feature in AutoCAD 2014.
"Select more than one layer in the Layer Properties manager and right-click to select Merge layers into a dialog box with a list of the current drawing layers displayed. Select the target layer, and after selection the previously selected layer(s) will be deleted/purged. Try it, you'll like it."
Notes from Cadalyst tip reviewer Brian Benton: Merge Layers To… is a new feature in AutoCAD 2014. It allows for easy layer maintenance. Users will be able to transfer all objects on a layer to a different layer and delete the selected layer. It is a quick way to clean up layers in a file.