hello,
i have installed esxi 5.1 on a macpro (finally supported) and it works like a charm. installed an osx mountain lion virtual machine.
but when installing the vmware tools, it shows the virtual machine as other (32bit) in the summary screen in vsphere client.
but that is just cosmetic. the real problem is that vmware tools crashes after several hours and that is annoying.
even tried to use the vmware tools supplied with vmware fusion 5.01 but it has the same behaviour.