Heavenly Sword and Jak are probably the only ones that might get revived, but Jak is owned by Naughty Dog and they seem to have moved on. It's usually good to let an IP die at some point, Jak is fine as a trilogy.
I just want Card Sagas Wars. Seriously, I'd do anything, just give me Card Sagas Wars. Please. PSN:ChocoboDreams
I would also love to see MediEvil 3 or Jak 4, but Naughty Dog said they have considered it but there was just no good direction to take the sequel to Jak 3 after the last games ending that would still appeal to the original fans
I actually think that a Medievil 3 is highly possible, if not already in development. When looking at the first-party characters in the game, most of them are either current franchises or obvious choices (Jak and Daxter for example). Basically, Parappa and Dan are the only characters that don't have a reason for being in the game other than they are awesome, but there are many other characters that are in a similar situation. Parappa was one of the four characters used to get the game green-lit so his inclusion can be chalked up to the awesome/nostalgia/personal preference of Superbot. Basically Sir Dan is the only character that doesn't seem to have any specific reasoning behind him. What I hope his inclusion means is that Sony is trying to raise awareness of Sir Dan for a future game, possibly already in development.