Did anybody ever used the new Spring3 with JSF2 and portlets (JSR286) ?
I used JSF1.2 with portlets (JSR168) we had some problems with stuff like file uploading, portlet intercommunication and other stuff.
There aren't a lot of resources online on this topic.
The Portlets in Action book covers JSR286, and has a couple of chapters on Spring3, but there's no mention of JSF2 sorry.
Much of JSR286 was done to address the problems in JSR168 with regards to file uploading and portlet communication. I would recommend dropping any JSR168 support in favour of JSR286 if you are able to.
UPDATE 1: Have you looked at the JBoss Portlet Bridge?
Using Spring 3 with JSF2 is pretty straightforward. You can use, for example, Sring Roo for building working Spring 3 configuration and then just plug in configuration required by JSF2.
However, currently there is no decent portlet bridge implementation that supports native JSF2. This pretty much undermines the whole purpose of using JSF2 with portlets, at least for now.
There is a small tech preview of JBoss Portletbridge (version 3.0.0, check this link) and for example Portletfaces project for Liferay Portal. However, both of these are in their early alpha phases, so they're not an option for production usage.