Imo, graphics won't make the PS4 the "best" and as a gamer, I don't need it to be the best to make me happy.. Much like the PS2, I expect Sony not to be the best in raw power next gen, but second place after the next X-Box and ahead of the WiiU. Games, innovation, and proper marketing will help it succeed.
My picks will go by the AMD rumors.
Processor:
AMD APU Trinity A10-5700 derived CPU clocked at 3.4 GHz* (At best)
The Cell processor will stay on board for BC. (Maybe for the first 2 or 3 years)
Ram:
1GB DDR3 1600MHz for the CPU and integrated GPU
GPU
AMD Radeon HD7770 derived GPU
Integrated GPU in APU will be 7660D and to have some sort of hybrid crossfire with discrete GPU
2GB GDDR5 (for discrete GPU)
Bluray drive
BD drive will stay but will be the latest (speed). Installations will be optional.
Storage
Sony should go flash. (8Gb?) This would bring down costs and since installations would be optional, it would be completely up to the consumer if he/she wants to purchase an HDD. Also, HDDs should be proprietary. (solid state maybe)
PS4 manufacturing to cost maybe $350. PS4 to retail at $350; break even or small loss.
It will also need to launch with Killzone "4" and Uncharted "4" as it would be a perfect way to market the PS"4".
Gran Turismo 6 would also be needed.
e=mc^2
Gaming on: PS4 Pro, Switch, SNES Mini, Wii U, PC (i5-7400, GTX 1060)