I have tossed Supermicro an Email asking for the real changelog for both the BIOS and IPMI Firmware. I will post the data when/if it arrives. If someone gets it before me, please post it.
I've been running both firmware updates for almost a week now. There does appear to be two fixes that I've noticed with the updated BMC/IPMI. PCH temp is no longer being reported as 0 a couple times a day, and I'm no longer getting the java update nag dialog in the web gui (note: I uninstalled java on my client prior to the updates, so perhaps I'm conflating cause and affect with respect to not seeing the java dialogs).