I'm not going to try and claim credit for this development, but Rich Brambley (the only blog with a description that I feel outshines my own :-) broke the news today that the free version ESXi 3 Update 3 appears to have a fully functional API. I plan on testing this out tomorrow, and will report back as I'm sure others will too!
UPDATE The great Mike D has beaten me to it. Looks like all systems are go for the evolution of statelesx... ;-)
UPDATE 2 Oh man... who the !#$% is running QA in VMware? What a shocker!