While they're not as retro as some, I'm impressed by your setup purely because all of those machines are the ones you use on a regular basis.

The other thing i noticed is that you're actually using OS X Server 1.2 apps on a regular basis, which I find impresive too. (You even linked to a machine running OpenStep on SPARC in another thread, if I remember correctly.)

It may not be fully "retro" as per the definition of the challenge yet, but I'd say in a few years it'll count, and right now, it's definitely pretty awesome.