Outstanding Dave!
There's a few designs on Thingiverse that might be a good starting point: http://www.thingiverse.com/search?q=wopr&sa=
Don't think I can 3D print this, I want to put like 50 or something Pi's in there. That's a lot of ethernet cable, switches etc.
But yeah, some good base designs exist.
I always wanted a life size WOPR, but, you know, wife, kids, space. Although technically I could build one in my bunker...