I resolved the ear file missing issue (it helps to use the right ant target when building).
I've now run into a strange error when JbossAs5.1.0 tries to deploy the application:
DEPLOYMENTS IN ERROR:
vfszip:/C:/jboss-5.1.0.GA/server/default/deploy/booking.ear/is in error due to the following reason(s): java.lang.ClassNotFoundException: org.drools.runtime.rule.WorkingMemoryEntryPoint
Anyone have an idea on how to proceed??