They're making Kingdom Hearts 3 for the PS3, that's like 99.9% definitely going to happen. It just likely won't be ready until...oh, beginning of next decade. And they know we don't really want to wait that long, so some of the team is making a few handheld games to hold us over. They're being nice, you should go with it.

And you can probably get a used PSP for say $130ish.