Among the many announcements made today during Sony's press conference at Gamescom, one of the really cool ones was the fact that Sony wants to make it easy and less expensive for gamers to play some hot, upcoming titles on both their current and next gen consoles.
While no price was given, Sony has said that people who purchase Watch_Dogs, Call of Duty: Ghosts, Battlefield IV or Assassin's Creed 4 for the PS3 will be able to buy them digitally for the PS4 at a significantly reduced cost. Gamestop is running a similar promotion on these games for the Xbox One (trade in the 360 version and get the Xbox One game for $10), and while they haven't extended that offer to the PS4 yet, I wouldn't be surprised to see something similar. I'm also guessing that the Sony will be matching that price with the digital offer.
Overall, this is a really smart move for them, as it will help bring in a ton of revenue on the initial release of these games on the current consoles for people who want these must-have games immediately upon launch while netting even more profit when they upgrade to the shinier and newer ones for next gen. And if the price point is indeed around $10, then most people will be more than happy to plunk down a few extra bucks for the upgrade.