Conversion of simple JS widgets to components means than you will have the widget to become first-class sitizen at JSF page and lifecycle. So it's really worth from reusability and maintance points of view.. Finally that's why we creating all that libraries
CDK 4 greatly differs from CDK 3.. and the complete documentation is really not ready for now. But you could already check what we have for it at our documentation page at http://jboss.org/richfaces.
Ok!!, so its worth doing of what i am doing now .
Thanks for your reply Ilya.