Building trunk or downloading a Hudson build http://hudson.jboss.org/hudson/view/JBoss%20AS/job/JBoss-AS-6.0.x/ is always an option. However, I don't know how stable the other components are when they were updated somehow. Therefor, I'd prefer to keep JBossAS 6.0.0 and just upgrade/exchange Weld.
You can then pull down the 1.1.0.Final tag of Weld,
mvn clean install -Pupdate-jboss-as, which updates Weld in your current JBOSS_HOME.