As currently designed, I'm mucking around in the VMX config file and invariably I have something hosed. When I click "Open" to start my VM and there's a config error or the VMM refuses to start there should at least be an error dialog to tell me to look in vmware.log.
I have found that the best way to detect an error in my .vmx file is with the system-wide console (/Applications/Utilities/Console.app), rather than by examining vmware.log.
When I try to power on a .vmx file with a syntax error in it, tyoically nothing at all is written to vmware.log. But the message in Console is very explicit: it even contains the line number.