I'm not sure how a thread pool is going to enable you to publish messages faster.
Can you be more specific about your perf problems? Using straight JBM you should be able to publish many 1000s of messages / second. Of course this depends on your messages size and whether your messages are persistent / non persistent.
My application processes requests and one of the tasks they do is putting a message in a queue, for performing additional actions asynchronously.
Then, I've seen in traces that the trask of putting the message in the queue takes about 300ms on a considerable pertentaje. As the application thread is the one who is performing this task, I thought an additional thread pool could be configured to deal sith this task, so that the calling thread would only give the message to those threads and continue its execution in a faster way.
I'm using jboss messaging 1.4.0.SP1 with persistence and haven't done any particular changes in configuration