I was able to use SNMP to get all kinds of info from my BladeCenter S - and specifically have it monitored with nagios. The original poster stated that the OIDs weren't documented anywhere.. but that is what the mib file is.. you just need to install it..
Here is how to install the MIBs from the IBM firmware (mmblade.mib) on ubunutu (requires snmp package):
copy mmblade.mib (contained in the firmware download) to /usr/share/snmp/mibs/BLADE-MIB.txt
(if you want alerts.. copy mmalerts.mib to /usr/share/snmp/mibs/BLADESPPALT-MIB.txt)
You now have access to over 10,000 settings.. you can get a complete list by doing:
snmpwalk -v1 -c public -Of ipaddress-of-bladecenterS -m BLADE-MID enterprises.ibm
and then for example, to find the front panel temperature:
snmpwalk -v1 -c public -Of ipaddress-of-bladecenterS -m BLADE-MIB enterprises.ibm.ibmAgents.netfinitySupportProcessorAgent.
which, although quite verbose.. is more human readable than
snmpwalk -v1 -c public -Of ipaddress-of-bladecenterS