I would like to see this also.
I realise you can see the date in the "Manage Appliance Certificates" dialog, but there is nothing to show what format the date is in - is it US or UK format?
Something unambiguous showing "Days until RADIUS certificate expiry" or the date as "17 September 2014" would be useful. That way the expiry cannot be misinterpreted.
Or perhaps support for NAC to obtain / renew certificates automatically using SCEP?
Thanks,
Mark.