While going through and cleaning up my ghettoSkunkworks projects folder before going on PTO, I came across this little post which I must have forgotten to publish. With the latest release of ESXi 5.1, there are now a total of 162 new vsish configuration parameters, with 63 of those being hidden parameters.
***As usual with any hidden configurations, please be careful and use at your own risk as the vsish interface is not officially supported by VMware***
Here is the complete list of new vsish configurations in ESXi 5.1 - https://s3.amazonaws.com/virtuallyghetto-download/complete_vsish_config_510.html
Thanks for the comment!