The Disappearing Act A VM went off the network, and actually lost the NIC from within the VM’s hardware.
Pouring through logs, (some thanks to LogInsight, more on that later), I discovered in vmware-xx.log:
2013-11-19T07:33:01.246Z| vcpu-0| Powering off Ethernet0
2013-11-19T07:33:01.246Z| vcpu-0| Hot removal done.
ah ha! This shows Ethernet0 was removed via the “Safely Remove Hardware” icon in the Windows system tray.
The solution is to add a new NIC of the same type.