Half Object plus Protocol Design Pattern for Portlets

Switching from one portlet to another results in losing the state of the first portlet. Due to this behavior of portlets, it becomes difficult to use them for rich client applications. Author Marc Domenig suggests half-object + protocol pattern (can't they think any better name?) can be useful in such scenarios.

Rich-Client Portlets And Half-Object Protocol Design Pattern

We have never faced such kind of requirements in our projects so I am not sure in what situation it can be useful. But It will be good to see similar support directly in portal servers.

What do you think? Have you faced similar problems in your projects?

Note: For those who are new to "Half Object plus Protocol (HOPP)" design pattern can have an introduction to it at http://jan.netcomp.monash.edu.au/distjava/hopp/lecture.html.