evaluating portal-portlet solution

Hi there,

Currently we are in the architecture design phase for a new client engagement. Amongst many ideas brought forward there is considerable focus on going forward with a portal - portlet solution. As i understand each portlet is a web application in itself. Now say if we model our requirements into portlet application we will be having around 20 odd portlets and they may or may not be individually apps neither do we have to show them in the same screen all juxtaposed next to each other.

My question here is if we have too much of inter portlet communication is it a good idea to model them as portlets or go for run-of-the-mill struts framework solution. Because we have an application flow and what I see is we will have too many inter-portlet communication like passing on few id's/context back and forth.
From whatever documentation I read I found inter-portlet communication is still not evolved in the JSR168 world and all vendors are providing proprietary solutions for the same.
Is it that in a portal - portlet world inter-portlet communication is to be used sparingly and not extensively.

Do post your thoughts.

Regards,