Quote Originally Posted by Cid's_Lady_Erin View Post
Crisis Core centers around Zack and the events with him leading up to Sephiroth's turning (I'm not sure if it goes up to his death or not). I think in it though he is, at some point, given a mission to track down a "rogue SOLDIER" who is (SPOILER)reported to be Genesis.

I think the secret ending means Square has an idea that they are thinking about. If they can't put it into a usable form, well they technically never said there would be a sequel. If they can put it into a usable form, well there was the secret ending to foreshadow its coming, so it isn't completely out of nowhere.
Very well put. This will all hopefully come together once Crisis Core is released.