In the 'Deployer Location and Naming' part of the Vendor-Specific Datasource Definitions[0] in the ACG, it says "... the $JBOSS_HOME/server/default/deploy/oracle-ds.xml directory ...". That should say the "... the $JBOSS_HOME/server/default/deploy/ directory ..." without the file name at the end of the path.

[0] http://docs.redhat.com/docs/en-US/JBoss_Enterprise_Application_Platform/5/html/Administration_And_Configuration_Guide/appendix-db-specific-datasources.html