I too am interested in this solution. I have an open Cisco TAC case asking them as well. My TAC case asks specifically how to monitor the standby supervisor. We experienced an issue where the standby crashed & we didn't know it, then months-years went by & the primary supervisor crashed & when it failed over to the standby we crashed.
Here is what cisco has to say:
"EEM will be the best option we also have another feature that is a little more complex to implement which is name Smart Call Home, that I also like to share with you so maybe you will like to implement, let me share with you the following:" http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/52sg/configuration/guide/callhome.html#wp1302128
"I will need to do some research to find out if we can actually monitor the Standby supervisor with this feature, as with EEM I think is possible."
"I just spoke with the EEM experts and they said that we can also send the SNMP traps to their solarwinds device as well also syslogging, etc... Using EEM, they gave me this link." http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/52sg/configuration/guide/snmp.html "They also direct e to this link:" https://supportforums.cisco.com/community/netpro/network-infrastructure/network-management