It's not that important actually. iPhone is a locked system hardware and software-wise. Whatever chip it's using now or in the future hardly matters.

On the other hand, adding these in the laptops might be interesting... But I don't think they are in a hurry to switch architectures so soon.

The iPhone 3GS already uses a custom chip. It combines an ARM processor, a SIMD FPU, a GPU, and 128 MB of DRAM onto a single die. It's pretty neat.