I also wonder the question.
When I check the JRun documentations in the page
http://www.adobe.com/products/jrun/productinfo/faq/eod/
I have following summary.
- JRun will not have any new "standalone" features.
- ColdFusion will continue to run on JRun J2EE server.
- When there is a need to update JRun to resolve an isse in
CF, there would be an update. (But I think this update will be
reflected as CF update.)
What I also guess is that you can still update the JRun which
you have with your multi server installation. But I do not think
that you are able to update standalone CF installations via a JRun
updater.