[Zope] zope zen needed...

I have a fairly large intranet site built on Zope. At first it mainly generated reports, but it is starting to be more of a web application then a reporting tool and I am thinking I need to make some decisions now about design. Eventually, I would like my users to be able to access the underlying services with a client other than a web browser. Do I carry on as I am and then build a client that accesses the zope objects via XMLRPC, or do I start making an external python API that I can then access through Zope or my other client(PyQT gui, PyGTK gui, etc.), or... Any advice appreciated.