It's pretty new (since 1.1.5 or 1.1.6) (hence no examples) but I have to say I find it wonderful (I use a mix of .page.xml and pages.xml - and there should be /path/to//view/pages.xml soon for a medium-granularity approach).
I find it fits *really* well with putting navigation in pages.xml - its all in one place. It certainly beats the propagation attribute on s:link (except for propagation="none") and means my backing beans are much cleaner and means that all the wiring is there.
Give it a go - the ref manual contains all you need to know IIRC.
I think its a good idea if you are trying to create more "reuseable" components, and separate orchestration out of the Java code.