One possible reason
Apple has the OpenCL technology in OSX to think about and that doesn't work on these low end chipsets.
Intel's Arrandale mobile CPU remains on schedule for an early January debut, but the word on the street is that one of Chipzilla's flagship customers will take a pass on that integrated-graphics part. That would be Apple. According to a report from Bright Side of News, "sources close to the heart of the matter" say that Apple …
Rik Myslewski writes, "Apple has asked Intel to build for them an Arrandale equivalent without the offending integrated GPU... Apple dumped integrated Intel graphics in late 2008 and moved to NVIDIA's GeForce 9400M for their integrated systems... Apple's current reliance on NVIDIA integrated graphics adds an odd twist to today's rumor, seeing as how NVIDIA and Intel are currently involved in a legal dispute over NVIDIA's right to produce platform chipsets for upcoming Intel processors..."
It sounds like Apple is defending their supplier (NVIDIA).
Apple seemed to defend their long-time CPU supplier (Motorola) through the AIM relationship when PowerPC for Apple was first released... instead of justs dumping 68K processors, they seemed to work in a process to give Motorola the ability to provide PowerPC processors to Apple and not just dump them for 100% IBM supplier.
At the same time, there has been very little discussion (lately) about that CPU designer (P.A. Semiconductor) that Apple purchased some time back... that seems vaguely related to this article and position that Apple has taken with Intel.
The history of suppliers, supplier relationships, and recent Apple acquisition seems to be a much more interesting story here than a decline to use one of dozens of chips that Intel is slated to produce.
Having used those lovely dual core atom nettops with the NVidia Ion chipset, I can only imagine how crippled they'd be without the GPU assist (WPAUG for 1080p playback with only 10% CPU load FTW).
Also, as the owner of a Macbook Pro with NVidia GPUs which make photoshop plugins fly, I don't see why I'd want that without the GPUs, too- plus I can plug it into a huge monitor, and still have a nice snappy gui and fast video playback.
No, Intel gfx chipsets are somewhat ghetto, do not want. I tolerate one in my netbook only because the machine was so cheap- and the lack of GPU does hurt on occasion (..and not just because I'd play Torchlight on WINE..)
Look, Apple and nVidia just spend a ton of R&D dollars developing Grand Central, which includes support for GPU generic processing. Intel's tech not only does not support this, but it;s integrated processor for Arrandale is substandard to nVidia's offering.
Apple has a great partnership with nVidia (and we all know they've allways kept the line to ATI open as well, and have been continually working with their parts in lab tests and system design as well). Integrating the Arrandale intel chip would make it difficult if not impossible to offer an additional onboard chip as they do with the nVidia 9400/9600M combo. We also know nVidia has some new mobile chips on the horizon (and already has a 9700 in the field). so we should be expecting a laptop refresh in Q1/Q2 using the newer chips.
Arrandale may be a good processor, but the GPU components are not as powerful as a 9400. Though there's some watts savings, it's limited to 1 or 2, which is fairly negligible, and even paired with an alternate GPU, the Mac could not use both the intel and nVidia (or ATI) concurrently as they do with the 9400/9600M combo meaning the top end graphics would also take a perfomance hit (in both GPU and CPU performance) and add complexity to the architecture design. it would also restrict minis and low end notebooks from using GPU acceleration technologies.
This is a bad plan any way you slice it. Apple DOES have the clout with intel (as their single most profitable customer by large margins) to get exclusive rights to chips as they're released, and also to sway intel's product lineup to their favor. I expect either an arrandale without a GPU being offered to Appple (one actually without it on die at all, not just disabled but present), and I also expect Apple, if they did use the chip at all, to have exclisive sales of it for 1-2 months before Dell and the others get it.