Look, you're all missing the point on this! (Errr, what is it?!)
The central thing is (it seems to me) a 12" CD won't fit in the standard CD player (non-standard ones in the entire world surely number in the hundreds at the moment) + you can already get a substantive amount of tracks on a 4" (or whatever the diameter, I haven't checked in a while ;) CD and with constant improvements in technology, this can only increase. Therefore a 12" CD is a redundant idea. The phonemes 'GIMM' and 'MICK' come to mind ... k