Well, I have done a decent amount of testing since:
1) The HDMI output from Windows requires PSU for HDMI detective with Vizio 3D HDTV and through Denon 1913 Receiver.
2) The HDMI output from Windows isn't sensed by older Onkyo receiver regardless of whether I use default 1080p Gefen EDID, Vizio 3D HDTV, or older Onkyo receiver.
3) The HDMI output from Mac OS 10.8 DOES NOT require PSU for HDMI detective and is sensed by Onkyo receiver as well as Vizio 3D HDTV and Denon 1913 Receiver.
Done on Base Mini 2012 model (2 separate machines with original firmare and latest update). So I'll be using the PSU on the HDMI detective for now, but I wish I didn't need the extra plug in use. Both upgraded with internal SSD in second bay, one with 16GB RAM and second still with base RAM.
I am not seeing display flickering, snowy, or black screens others have noted... so far.