Game consoles have peaked in the market, with a total of 225 Million units sold.
While the current crop of Consoles were "King of the Hill" when they were released in the early to mid 2000s, and people splashed out 40 - 60 Dollars to buy a game for them, today the market looks very different.
Games for smart phones & tablet computers are becoming more and more popular, and more sophisticated with time, driving significant gamer traffic away from Consoles.
Both smart phones and tablet computers are getting more powerful quickly, hardware capability-wise, meaning that they will eventually be able to run "Console Quality" or "Near Console Quality" games natively.
The many new "Free to Play" multiplayer games for PC, which make money from Micro-Transactions (buying items/weapons/powers/perks for use in the game) are also driving casual gamers away from Consoles.
The convenience of cloud services like Steam is also leading to a rebirth of PC gaming, which was much neglected in the mid 2000s, when publishers suddenly started targeting Consoles instead of the good old PC.
Basic Summary: The IT landscape today looks very, very different from when PS3/Xbox 360/Wii were released. To make it in the market, the coming 4th Generation of Consoles will have to offer a lot more than "Just sit on your couch and game!". Selling Console games at high prices like 60 Dollars per game may no longer be economically feasible in this new market landscape.