If the PS3 isn't profitable in it's lifetime I'd say they'll change the design of the PS4, maybe make it cheap and main-stream friendly.
But even if the PS3 isn't yet profitable, it's an important market share for sony, not just with games but also as a Blu-Ray player and 3D capabilities.
SCE isn't Domed, and aren't committing suicide, sorry to let you down OP.