The (to be) attached patch implements the following semantics in xfwm4:
- Create a workspace in the location adjacent to the active workspace
- Delete the active workspace

I find these more natural since I often find I want a new workspace when the active one is getting crowded.  Creating the new workspace in the adjacent space allows me to easily maintain task locality (among workspaces), where otherwise I would either have to split the task among the active and the rightmost workspaces, or manually shift every client one workspace to the right.

Deleting the current workspace is also very natural, and also provides an easy way to undo accidental application of the above functionality.

Some people on the xfce4-dev ML suggested that these semantics replace the standard ones, given their intuitiveness.  Such a change seems reasonable.  The main drawbacks I can see are that these semantics take a bit more computation (though, on most machines, it likely won't be noticeable), and that people may have gotten used to the other behavior.