(plus there's a good chance I won't be getting a PS4 -- definitely not in the first few years for sure at least. I won't say 'never' 'cause it might turn out there's stuff I want afterall. ... Like what happened with the PS3.)
Nope. If this was coming to PS4, Square Enix would've said so at the PlayStation Meeting. At the moment, it's just a PS3 exclusive, which makes sense as it likely wouldn't sell well on the PS4 anyway, since the game's target audience probably won't have a PS4 early in its lifetime.
Why would they put it on the PS4? That'd be pointless. If you're selling your PS3 when the PS4 comes out, I'd suggest re-thinking it, because the PS4 isn't going to be compatible at all with any of your disc-based PS3 games.
I only even have a PS3 because someone bought it as a gift. Otherwise I would have just stuck to PC. I'll buy certain games for PS3 if I know I only want to use a controller for it and want to do achievements.
Unfortunatly, KH3, or any KH game can't be on PS4 because Disney does not support digital downloading, the PS4 does not support any disc-based game's, only digital download's from the PS Store, so as of right now there can't be any KH games on PS4, sorry people.
Just to play devil's advocate, S-E has been known to renege on its promises: FFXIII on 360; Canceling PS3 The Last Remnant quietly, and the jury still being out on FF Versus XIII's fate. They might just be keeping quiet and intentionally not revealing too much info. I've learned to take what they say with a grain of salt, and I'll believe when I see.
As is well known, the KH3 release is a subject of much rumor and speculation. According to some sites, the project has yet to begin development, due to series creator Tetsuya Nomura being focused on Final Fantasy Versus XIII.
Anyone beginning to see a pattern since it's the same creator?
Worst part is KH3 is supposed to be the series' conclusion (unlike FFVXIII where it's a standalone game with a new story) so it would really be bad if it's never released. Let's just pray and hope it doesn't end up as vaporware.
KH 3 is not the series conclusion. Nomura said a long time ago that KH 3 will just finish the current story arc and a new plot will be developed afterward. The current list of games is part of the Xehanort Saga and it will end with KH 3, after that a new plot and antagonist will be introduced and Nomura also stated that Sora will ALWAYS be the main character and his role will not end until the series does.