The guys at vinternals launched a very interesting tool called Statelesx (clearly meaning Stateless ESX).
This tool allows the VMware administrators to define a configuration file on a web interface (including details about the virtual networking, the DRS, the HA, etc.) and associate it to a certain ESX by the host name.
To spread the configuration file to the proper ESX host, statelesx uses a Python script and a Java listener available as virtual appliance.
The whole thing, working with VMware Infrastructure 3.5 only, cuts away the need to configure a new ESX on deployment and backup its configuration over time. But most of all it avoids inconsistencies across the virtual infrastructure:
The tool already hit the 1.1 version. Download it here.