I think the main weakness is the lack of appeal for consumer beyond current PS360 gamer market.
Bluray/DVD is too common, it dont have a wiimote-like, there is no wow factor compared to PC, casual/indie can be played for a large part on smartphone, I can't see any super-uber feature.
But being that way, the PS4 is currently catching most of the population coming from PS360, so it could be good enough !







