Adding components to hierarchy

If drag and drop doesn't work (listed in known issues), how does one add something from the project window, e.g. a prefab, to the hierarchy?

Until I get this figured out it sort of makes prefabs useless (or at least really hard to use)

 

You can drag and drop prefabs in the scene window. It's a bit buggy right now because there is an offset to it (the item gets placed some way down from your cursor) but it's ok to work with.