HornetQ provides a HTTP transport and a Netty servlet to access JMS resources over HTTP.

http://docs.jboss.org/hornetq/2.3.0.CR2/docs/user-manual/html/configuring-transports.html#d0e3665

This involves a lot of configuration tweaks that could be handled by the messaging subsystem so that the users just have to specify a http-connector (or servlet-connector) and the messaging subsystem will figure out the rest (find or create a web container, place the netty servlet into it with the appropriate web.xml configuration, etc.)