I just saw that the opensolaris net-snmp software was updated to version 5.4.1:
Author: Vijay HN
Latest revision: 739325d040fb9f332a2ae9e196de38e06f1ec81b
Total changesets: 1
LSARC 2008/355 System Management Agent (SMA1.0) migration to Net-SNMP 5.4.1
6848323 ON package changes required for SMA to net-snmp migration
This is a welcome addition, and will provide admins with a number of new capabilities (e.g., disk monitoring) that aren’t available in the net-snmp 5.0.9 build that is currently part of Solaris!