A remaster of Demon's Souls has been a long time request of Souls fans. The game was a PS3 exclusive, and quite frankly it ran like dogs*%t. There has never been a game more deserving of, or in need of, a remaster. Fixing the frame rate, upping the resolution, and maybe working out a few kinks would make Demon's Souls one of the best games on offer for the PS4.
However, Miyazaki stated that From Soft wanted to move on when asked about a potential remaster for the game that really put them on the map. It seemed like the dream was dead until more recently where he clarified the situation:
“It seems like there was a misunderstanding in a previous interview in relation to a remake or a remastering of the game, so let me reiterate here.
The Dark Souls series is Bandai Namco Entertainment's IP, and Demon's Souls and Bloodborne is Sony Interactive Entertainment's IP. Hence, the decision to do a remake or remastering is under their jurisdiction.
For me and for From Software, I don't think we'll be involved with their happening, but it could happen through another developer.“
So there you have it, Sony owns the IP for Demon's Souls and Bloodborne (stop f*$^ing port begging) and it is up to them whether or not it will get done. From Soft is busy on the DLC for Dark Souls 3 and have put their plans for an all new IP into motion, but that doesn't mean a solid team from outside From Soft can't tackle the challenge.
Straight from From Soft: Sony owns Bloodborne. That means you'll never get a port, stop asking.
Using a third party for remakes doesn't mean a decline in quality either: Nintendo has used a few third parties to remaster their big game, Grezzo, Monster Games, and Tantalus most notably, and it has worked out amazingly well for them, with most remasters being huge improvements over the originals. Hopefully Sony can find a good team that's more than capable of dragging Demon's Souls into the 8th gen, and making it stable for the first time ever.
[Source]
