For Sony, at this point it's probably still Final Fantasy despite the amount of decay.
Things like Tales, Resident Evil, Yakuza, Metal Gear, and Kingdom Hearts will help, but I don't think any will inspire a level of confidence in other developers to follow through on their own volition.
What they really want though is just as much software as they can possible get. Thanks to the West, they will have a few guaranteed big hitters. Beyond that, Sony needs to do what they did for the Vita and just mass bribe as many developers as they can to put content on the PS4 so people aren't just buying it for one game. Filling in the bottom to lower-mid tier here is something that might work better than Vita since they actually have a few big hitters due to externalities.
That said, this will be a long uphill battle.