Are these different services with different WSDL interfaces? Then this will probably not work as both services would subscribe to the same JMS queue and potentially receive a SOAP message that they cannot parse (as it was intended for the other service). You could potentially try to use Message Selectors but I don't see any gain over simply using two different queues.
If both services have the same WSDL interface, then it should work, although I have never tried it. You can implement a sort of load balancer that way with having both services subscribed to the same JMS queue.