The list is short, but critical, and impacts both ESX 4.0 as well as ESXi 4.0 hosts.
ESXi400-200907401-BG – Critical http://kb.vmware.com/kb/1013016
This patch fixes the following issue – If the RAID controller battery backup unit is completely discharged after a shutdown, or if a locally attached disk is removed and not returned to the system, data corruption might occur because the RAID controller cache is not cleared while shutting down the server. See KB 1013016 for more details. NOTE: Cisco Nexus 1000v customers using VMware Update Manager to patch ESXi 4.0 should add an additional patch download URL as described in KB 1013134
ESX400-200907401-BG – Critical http://kb.vmware.com/kb/1013026
This patch fixes the following issue – If the RAID controller battery backup unit is completely discharged after a shutdown, or if a locally attached disk is removed and not returned to the system, data corruption might occur because the RAID controller cache is not cleared while shutting down the server. See KB 1013026 for more details. NOTE: Cisco Nexus 1000v customers using VMware Update Manager to patch ESXi 4.0 should add an additional patch download URL as described in KB 1013134