There hasn't been much interest in such a feature (http://jira.jboss.com/jira/browse/JBCACHE-311), and as such, I'm not very keen on increasing prio on this one. It would be a ncie to have, but at the moment a lot of the internal code relies on JGroups. The channel is one example, but all invoke() calls on the interceptors take in JGroups MethodCall objects.
There are plans to move away from MethodCalls and reduce the dependency on JGroups - such as http://jira.jboss.com/jira/browse/JBCACHE-468 and http://jira.jboss.com/jira/browse/JBCACHE-198 - and these will have to be done before we can consider making JGroups an optional transport. That said, even these plans are not high priority and a bext guess on some of these would be around Q3 this year.
I appreciate your situation and your inability to use JGroups for whatever reason, but given the current workload and feature list on our plate, I don't realistically see JBCACHE-311 happening very soon.