Depends on how you define success. If you define it by the amount of systems sold compared to its competitors, then no. Neither would it be if you compare the amount of systems sold to its predecessor. I think the most important question that sony should ask itself is "Covering the entire generation, did the PS3 make money?" It's hard to make an estimate of the amount of money that Sony invested (R&D, hardware manufactoring/distribution, software development/maintenance costs) versus the amount of money they earned (first and third party revenue, maybe profits from sold systems), but if I had to take a guess, I think they made money in the end.
Besides, it's the most successful console to ever finish third in the console race. That's gotta count for something ;)
