This is all nice and dandy, but what if you do want to "jail break" a service from a plan? Well there is a very simple way to do it. As Glyn describes in this thread on SpringSource dmServer forums, it's as simple as adding a service property.
<service id="publishIntoGlobal" interface="java.lang.CharSequence">
<beans:entry key="com.springsource.service.scope" value="global" />