VMware has made available update 1 for vSphere ESX/ESXi and vCenter, providing patches and enhancements, like support for additional guest operating systems and processor support. This update can be applied to vSphere 4.1, which was released in July last year.
ESXi now provides support for using Trusted Execution Technology (TXT) from Intel and available now on Intel Xeon 5600 series processor types. TXT can protect ESXi in some cases where system binaries are corrupted or have been tampered with.