If you've read my posts, you know I'm a firm believer that the room is as important as the gear you put into it.
My list for dedicated room:
Dedicated Power - I'm even considering running the same wire the Zen Styx are made from between the breaker box and dedicated outlet.
Lots of wood! I like a very live but controlled room. I plan on thick carpet with good padding, well placed broadband and bass absorbers, and lots of hardwood diffusers!
Low noise floor, both acoustically and electrically - so heavy, well insulated walls, windows plugged, insulated (diffused) ceiling, and the aforementioned Faraday Cage. :D
Wrap it up with a comfy chair and Decware gear and I'm all set!