If you want to get the full collection of VMware metrics, and not just the logs - you will want to leverage the OVA image that Splunk provides to get you the required Linux based components. That is because the components that work to collect that info (Scheduler and Data Collection Node) only run on Linux. See: http://docs.splunk.com/Documentation/AddOns/released/VMW/Hardwareandsoftwarerequirements for more details
If you just want the ESXi logs, then the full blown add-on may not be required, and you can probably just get away with the Splunk_TA_esxilogs , from the add-on.
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