Need a mechanism for the virtual machine to inform Hudson of its IP address
(event when it does not have VMware tools installed)

I'm thinking that the VM just does a http POST of it's IP address(es) to

/hudson/plugins/vmware/SOMEKEY

Hudson can then look at the request client IP address and see which of the
passed back IP addresses match the request. If none match, then it can try
routing to all the passed IP addresses. If it still can't connect... then fail
the build.

Once it knows the IP address, it will set an environment variable (SOMEKEY in
this example) to the IP address so that the build can pick up the IP address