In the Weld 1.1 Beta 1 release, the @Observes API has an annotation element changed. This is an incompatible API change and would break existing clients.

– The original API for @Observes –
public interface javax.enterprise.event.Observes extends java.lang.annotation.Annotation{
public abstract javax.enterprise.event.Reception notifyObserver();
public abstract javax.enterprise.event.TransactionPhase during();
}
– The original API for @Observes –

and now it is:
– The new API for @Observes –
public interface javax.enterprise.event.Observes extends java.lang.annotation.Annotation{
public abstract javax.enterprise.event.Reception receive();
public abstract javax.enterprise.event.TransactionPhase during();
}
– The new API for @Observes –

Notice the renaming of "notifyObserver" to "receive". The original name for the annotation element "notifyObserver" has been published earlier as part of Java EE 6 javadoc [1]. However in the JSR 299 specification, the annotation element is referred to as "receives" (See Section 10.4.3) and hence I think this have been renamed as part of WELD-455 [2].

Please revert this change in API.

[1] http://download.oracle.com/javaee/6/api/javax/enterprise/event/Observes.html#notifyObserver()
[2] https://jira.jboss.org/browse/WELD-455