Considering the current iMacs and the Macbook Pros have so many components in common, why doesn't Apple improve the graphics card of the iMac's (or at least the top-of-the-range one) to match the ones in the MacBook Pros? The benchmarks put the GeForce 8600M GT so far ahead of the Radeon HD 2600 PRO. Is it to do with cost? It can't be heat issues, as the MacBook Pros are less than half the thickness on the new iMacs. Are there any newly announced mobile graphics cards from either Nvidia or ATI that would be suitable for Apple to use in the next revision on the iMac?