I am relatively new to this area in specifics and need to know if real-time java is ready for enterprise level use. I am interested in connecting two very large systems A and B where we must have a priority schema and a QoS plan with guarantees for delivery in performance demanding circumstances.
The simple answer is "yes", but whether real-time Java meets the requirements of your system is something that only you can answer.
You posted this in the "Distributed Real-time" forum and "Distributed real-time Java" exists in name only as JSR-50. Regular real-time Java (JSR-01) can be (and is being) used in systems that involve distribution, but the communication channels between two real-time VMs is not covered by the real-time specification nor its implementations. Even JSR-50 assumes a real-time transport layer.
All I can do at this stage is recommend that you download Java RTS for evaluation and see what it can do for you. There are various links to additional information from the main Java RTS technology page:
Note that our 2.1 final release will be available in a couple of days.
If you have further questions feel free to post them in the regular real-time forum.