Well, Starfox 2 doesn't need to be on a seperate disc, they could just put that as an unlockable or option on the regular game disc.
They really need to do something about that game, though. It was reportedly 95% complete at CES. Two ROMs of close-to-complete versions (need some bug fixes, especially having to do with Star Wolf's team) have floated around the net. It's a quality game, too, it just got cancelled for politics, since it was so late in the SNES's life cycle and Nintendo wanted to only promote the upcoming N64 version.