It eliminates the ??? step:

Step 1: Release Core 2 Duo

Step 2: Release Core 2 Duo now that they're practically free

Step 3: Profit.

I think the point is Apple prefers the 13" Macbook pro having the more powerful NVIDIA integrated GPU over the iX Intel Core CPUs's Intel HD integrate GPU.

Not to be snarky, but, we know :)

"We chose killer graphics plus 10 hour battery life over a very small CPU speed increase. Users will see far more performance boost from the speedy graphics" (Steve Jobs).

No amount of CPU would make the NVidia 9400 faster. It's simply a dog.