TweakTown reports Sony filed a patent for a new type of in-game advertisements that stop the game in order to show an advertisement. Lets hope they don't plan on using it, and definitely not in non-free games.
Now, advertising is fine when it is paying for things like broadcast TV, but if a user shells out $60 for a game like Call of Duty, I imagine that user is going to be a bit upset. Additionally, if this is used during multiplayer settings, every user would need to be shown the ad at the same time or the game will be broken beyond repair.
This patent does have uses for free games. Similar to how games are ad supported on iOS and Android, free games on PlayStation could become ad supported. But with the multiplayer issue, users could only be paired with other free users or users would have to be limited to only single player play. It is an interesting idea.