I'm tracking down a similar problem, trying to get JSF2 (Mojarra) working with Seam 2.2.1 CR1. I removed jsf-api.jar and jsf-impl.jar from my webapp and changed faces-config.xml to declare v2.0 and remove the FacesViewHandler.
However on deployment in JBoss, I get this exception:
2010-04-16 11:24:18,249 INFO [javax.enterprise.resource.webcontainer.jsf.config] (Thread-2) Unsanitized stacktrace from failed start... javax.faces.view.facelets.FaceletException: Must have a Constructor that takes in a ComponentConfig at com.sun.faces.facelets.tag.AbstractTagLibrary$UserComponentHandlerFactory.<init>(AbstractTagLibrary.java:289) at com.sun.faces.facelets.tag.AbstractTagLibrary.addComponent(AbstractTagLibrary.java:519)
Looking at the examples included with Seam, none of them are using JSF 2.
Im with the exactly same problem!! im trying to upgrade my app tu seam 2.2.x with JSF 2. The problem seems to be that the seam components point to the ViewHandler class that is located in the facelets.jar ... and in JSF 2 you dont need this jar.
I tried many ways, and my conclusion is that you just cant remove the facelets.jar from you seam 2.2.x app because seam components need this old jar references.
Try to remove seam-debug.jar and them remove the view hander from faces-config.xml, and you will see in the console what im talking about.