It's been a while since I wrote the first post on this thread. That's because I've tried to steer my customers away from ML servers. Apple would have been much better off to make Profile Manager a downloadable app, perhaps bundled with OD. They could then drop the pretense about offering a server product that ticks feature boxes but isn't any good at any of them. It is the exact opposite of the way Apple seem to approach the rest of their business.
I've had to try and set another one up today and found the exact same problem. HT5390 doesn't work. Please don't anyone reply by pointing me to it. I know about the article. That's why it's in the thread title. It doesn't work. If it worked I wouldn't be here. Port 5900 is not open out of the box (same with 22), there is no VNC service running. Using the Server app doesn't work either.
Bottom line is that even with the newest Mac Mini Servers (Late 2012) there is no way to set them up without a display, keyboard and mouse. At least until you can get far enough along to enable remote management.
Has anyone tried with a Mac Pro Server (one that has server installed out of the box)? Is headless server installation on the Mac platform completely dead?