Hey guy in IT. (I don't know if that means information tech, or italy)
I'm presently writing a perl plugin to manage our two ME4012s. If you're interested, please comment here.
Really, the best way to manage these is going to be the same as I did for the iDRAC: Do a full SNMP walk of your unit *including* loading the right Dell MIB so that you get the proper values for connUnitPortStatus and connUnitStatus, read all the data, and look for any values of "ok", and watch those.
The other thing you could do is parse the events (which seem to be exposed via SNMP) and look for any critical event.
As I read the MIB I don't see any disk or volume specific descriptors.