I think more stuff will come out regarding the GC when the gameshark comes out.
BTW only the panasonic GC can read full size DVDs, even if you put the guts of the machine into a larger case, the laser lens can't reach the end of the disc.
I think the best bet will be an external CD reader as rumours have been flying around aout. Another rumour is that the security on GC discs are on a mini barcode at the beginning of each disc. (sure is looong)