One of the products that I have been keeping my eye on over the last few months from Max Daneri over at VMware Labs, is the PXE Manager for vCenter that was released in April of 2011. The main goal of this tool is for automated provisioning of large quantities of ESXi nodes (Sorry, no ESX) and provides host state firmware backups, restore capabilities and archiving. You can also link this product with multiple vCenter servers and also has patch management options integrated within the tool.
Installation of the VMware PXE Server (Manager) side of this product is a simple executable (vpxecmd.exe) that is run on a stand-alone server or vm within the environment. You will need admin control of the vCenter server to complete the install and it actually creates a WebServer with self-signed certificates for it. During the installation phase, you will need to specify the FQDN or NetBIOS name of the vCenter server and cannot use an IP address. *One word of caution, if you are using the stateless feature, you must install and configure Microsoft NFS server.*
The other part of this is the VMware PXE Plugin that is installed from within the vSphere Client, just like any other plugin that you enable through the client. When it is downloaded and the install is complete on the client end, you will see a Solutions and Applications section in the Home folder of your client to access the new PXE Manager.
More great integration with this client, is the ability to deploy directly to vCloud Director as well as to Cisco UCS blades. Additionally, you can run MEMTEST on your hosts which could be quite handy for diagnosing problems.
Might have to do a follow up to this post when this product becomes more mature and is enhanced since I see this as a great asset to keeping the cluster uniform in conjunction with host profiles. Best of all, it is free!