Airplay to more than one screen concurrently? I'm looking for the best method to display a desktop on multiple television displays. Currently I have a Mac Mini mounted behind the tv and controlling via vnc. As I want to setup more screens (All with the same desktop view); I am thinking I could use the Mini as a server; and then mirror from there to multiple Apple TVs on the same network via airplay.  As I haven't ordered yet; is this possible? I can't seem to find any mention anywhere whether this would work.  Any other suggestions would also be welcome.
I just tried it with my mid-2011 Mac mini running 10.8.  I can choose to mirror to either of my ATV's, but not both at the same time.  One ATV is version 2, one is version 3, which could have some effect (they are different native resolutions), but I somehow doubt that's a factor.  I'd think multiple mirroring could create quite a demand on the GPU and the network, so I don't think it's supported.