If you really think about, if the PS4 really does come out next year at some time (probably holiday 2012 at earliest) then a complete redesign makes sense.
However, there's little chance for functionality increases so long as the PS3's limitations are still in effect. Live was only able to truly able to upgrade everything once the previous system was taken offline completely.
That will be interesting though since so many games are reliant upon patches this gen. Trying to play those games in the future glitch free may be next to impossible depending on how things are handled.
I'm not saying Drake is classist or racist, but he does hate poor minorities. ~ Jakyl