I know VMware provides a supported "scripted installation" of ESX server 2.5.4; however, I wish to know is there a supported or un-supported method to either run the installation of patches after the ESX Server installation or slip stream the patches into the installation?
Here's some good links to patching...
Autopatching ESX host - http://virtrix.blogspot.com/2007/03/vmware-autopatching-your-esx-host.html
Patching and updating Vmware ESX Server 3 - http://download3.vmware.com/vmworld/2006/tac9858.pdf
Patch Management for ESX Server 3 - http://www.vmware.com/pdf/esx3_esxupdate.pdf
I did this with the 2.5 tree. Definitely on the unsupported side. I never documented the exact steps, but did write down some notes in this post.
It was fun to figure out, but I would never deploy a production or really even a test system with this.