What specifically are you wanting to monitor?
There's a lot of stuff you 'can' look at if you want to:
http://download.oracle.com/docs/cd/B28359_01/server.111/b28321/strms_qpmon.htmI personally look to make sure the queue status' are ENABLED. I also check table counts between the replicated systems.
The number of messages in the queues might be useful depending on your specific requirements.
