If I recall correctly, Arrandale does not yet have support for OpenCL. It's in the works, but it's not there yet. In terms of raw performance, Arrandale is co

If I recall correctly, Arrandale does not yet have support for OpenCL. It's in the works, but it's not there yet. In terms of raw performance, Arrandale is competitive with the 320M (maybe a wee bit slower). Overall, Arrandale will be attractive to Apple with OpenCL support, since they no longer need two chips -- just the CPU package which has everything it needs (graphics, memory controller, etc). That allows space for better thermal solutions, more memory or SSD storage, a larger battery, or other functionality. Hence the decision to stay with the current nVidia 320M and Intel Core 2 Duo -- once Arrandale supports OpenCL, we'll see Apple transition. Not only for the MacBook Air, but also likely in the MacBook, low-end MacBook Pro SKUs, and the Mac Mini.