Does Parallels 5 have a headless mode now? I mean can I start a VM and then disconnect from it and have it run in the background (and reconnect later)? I don't want to suspend or shut down VMs just because I want to log out of Mac OS or quit the Parallels GUI.
There is no official way to do it. But virtual machine keeps running without GUI if Parallels Desktop quits unexpectedly (crashed or force quit). Therefor you will not lose your work in Virtual Machine, just relaunch Parallels Desktop.