I'm also thinking of doing something fun with this build. Just to try something different, I'm thinking I'll make this a caseless build.
Here is my current desk setup. The computer is currently in a case in the lower left cabinet. It takes up the whole cabinet. I was thinking that I would mount the motherboard to the desk hutch behind the right monitor. The only other item to place is the power supply which can probably sit on the desk behind the monitor. This frees up the cabinet for storage and/or other use. I'm not planning on fancy lighting or anything like some wall mount designs do, but it would save some space, and look a bit more geeky (which I like).