First of all, thanks a lot for nice piece of code... I managed to integrate it nicely with Mule 2.2 and succeed to use XA (in standalone tomcat) with IBM MQ, Oracle AQ and Oracle JMS... It works like a train.
Only one think, i experienced deadlocks in JMSPooledConnection under heavy load in multythreaded environement. Changing the code to use Java5 semaphores did the trick. ;) All is good now.