seam application using jboss-seam-2.0.0.CR1 jars on jboss-4.2.2 could be upgraded successfully to jboss-5.1.0.GA
using jboss-seam-2.2.0.GA jars. Richfaces jars that come with jboss-seam-2.2.0.GA also supports for User Interface and no seperate download of richfaces was required. "seam2migration.txt" inside jboss-seam-2.2.0.GA will be of help.