What is most disappointing about the whole thing is that MCP99 was supposed to be twice as fast as the 9400M (32 shaders instead of 16 - I'm sure Nvidia would have sold crippled versions with 24 or 16 shaders to allow for lower power consumption too). So we went from having 200% of the performance we have now to 60%. Yuck. I would hope that Intel had to give Apple a sweetheart deal on these new Arrandale chips to get the business back from Nvidia and basically put Nvidia out of the chipset business.
The 240M will likely be 5x as fast, using the 9400M as a reference point, Arrandale is 60% and the 240M is 3x as fast, so 5x total improvement.
Apple isn't likely to extend the battery life much beyond 7-8 hours, what happens is that Apple's customizable battery design means they can put exactly the amount of battery power in a laptop as they want, and reduce the total weight or thickness of the laptop. Shave a quarter of a pound or more off a laptop.
It could make a huge difference in the MBAir - its 18W CPU and 10W 9400M becomes 18W + 4W, plus less heat (!!!) and less room on the motherboard required so they can cram even more battery into it (the MBA could use a boost).
Don't underestimate Apple's ability to spin the decision to use a less powerful GPU. They'll come out and talk about dual 1080P HD video decoders and better battery life, or how they made it even lighter and thinner. The RDF will be in full effect.
Improved battery life doesn't matter for the mini or imac. But it also ties in with possible price reductions too. Remember Intel goes from selling CPU+MCH+ICH to CPU with GPU and most of MCH + PCH. Apple probably wants to get a $999 iMac in there, and this could help.
Well there is no way Intel is going to put an Nvidia GPU on package, and Apple licensing DMI for Nvidia doesn't seem too likely. Adding any sort of integrated video that isn't Intel to these Arrandale chips isn't really possible, it'll have to be a discrete GPU with its own memory ($$$). The memory controller is on the GPU die itself (not the CPU!) and the only connection is via DMI. There is the x16 PCIE connection but I don't know if anything hanging off that port will be able to use system memory as graphics memory. Maybe.
I wouldn't say every mac would have a discrete GPU - the bottom of the lineups in each category will undoubtedly have chieapo graphics just because its cheap.
Also, the dual HD video decoders would make this a good time to add BR.
