Intel revoked NVIDIA's GPU license for the Core i3/i5/i7 processors. Or something to that effect. Also, Intel made the Intel HD graphics chip into the CPU die itself. There's no way to separate or deactivate it. And due to space and power constraints, there's not enough room to do the "NVIDIA 9400M/9600M GT" combo like before. In conclusion, it's just much easier to add a powerful NVIDIA GPU to an existing Core i5/i7 with integrated graphics.