All the info available so far suggests that it will run on all intel macs. I guess that macbooks just won't be able to take advantage of programmes optimised to use the GPU.
I think that they will still be compatible with Snow Leopard, they just might not be able to take advantage of some of the new GPU features that Snow Leopard will present. I think that it is highly unlikely that Apple would essentially drop support of computers that are under 2 years old, yet alone computers that are only months old.
I think that it is highly unlikely that Apple would essentially drop support of computers that are under 2 years old, yet alone computers that are only months old.
I remember long after the specs for Tiger were released Apple were still releasing products with no Core Image compatibility.
All that will happen is that current Macs with integrated graphics will be able to run everything just fine and Apple will eventually replace them with some chipset that has the barest minimum of dedicated graphics grunt just to give them a leg up.
What we will see is a big jump in performance between the MacBook and the MacBook Pro which I think is good. The difference for most people between the MacBook and the Pro is very little at the moment. A big leap in grunt would go a long way towards better product delineation.
If you've got an Intel Mac, whether it be a notebook or a desktop, Snow Leopard will work- and it will likely make what you have even faster.
If you're not sure whether you've got an Intel Mac or not, you can click that little Apple up in the upper left hand corner, and click "About This Mac".