I think Sony has written off this gen from the standpoint of achieving financial sucess from the PS3, so there's no point in talking about it any more. It's lost them money and that's that. Best thing that can be said from an economic perspective is that they lived to tell the tale.
So the only form of success they can salvage is of the PS brand itself. The brand, as Squill has pointed out, has lost a butt load of street cred and hence value. BUT, the brand is being rehabilitated as we speak. The PS brand is improving its credibility through PS3 in the eyes of the media and markets, but it still has a way to go before it returns to the sort of favour PS2 achieved for the brand. I think it might get half way back by the close of the generation. The rest of the job will have to be on PS4 and (if there is one) PSP2 to achieve.
PS3 could have been "the decline and fall of Rome" for Sony. Fortunately Sony managed to turn it into the "Fall and Rise of Reginald Perrin".
So in absolute terms PS3 has been an unsuccessful genersation for Sony. But in relative terms PS3 will succeed in keeping the PS brand alive and giving the next PS console a reasonable launching pad.
It's then down to whether Sony screws itself over for a 2nd time in a row. (3rd time in a row if you include PSPGo.)
“The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.” - Bertrand Russell
"When the power of love overcomes the love of power, the world will know peace."
Jimi Hendrix







