I have a partially nintendo case at home. (not sure if I have the neccesary hardware, but hopefully I can get it). Neil picked up a slimline cd-rom drive and ITX power supply at the dump and run that hopefully can be taken and used in it. (The problem with the drive right now is that it's a Macintosh docking port connector, and I don't know if I can pull that out to IDE, but that's a concern for later.)
At this point, what I basically need is a laptop hard drive (100 bucks ish on ebay?) and a mini-itx motherboard. The motherboard will cost about 100 plus shipping. all the components (video, sound, ethernet) are built into those motherboards, so with creative use of Neil's dremel tool cutting the back of the nintendo to fit it in shouldn't be too difficult.
There is something cool about a machine inside a Nintendo Entertainment System. It's ultimately portable, albiet not a powerhouse machine. But can you imagine the looks I'd get when I bring in my pc to check something out - and it looks like I could pop a cartridge into it?
This is such a cool idea.