While the move to Intel processors has been incredibly beneficial for Apple in terms of computer sales, there are rumors that the chipset its Macs are currently running on is perhaps no longer adequate and thus the company is looking for a suitable third-party alternative.
Some say that Apple may develop its own chipset, others have shuffled ATI and VIA as possible candidates, but an interesting piece over at PC Perspective puts Nvidia as the only likely suitor. Ryan Shrout claims that with Apple's current partnership with ATI on discrete graphics it would only seem logical for the company to use their chipset technologies in upcoming products, but such a move would entail switching to AMD processors - which is very unlikely.
He also discards VIA Technologies, well, for the mere fact that their chipsets compare unfavorably with competing parts from Intel so it wouldn't make much sense. However, Shrout thinks that Apple has every reason to choose Nvidia's upcoming MCP79 chipset, which is an Intel-compatible product that integrates a DX10-class graphics core with support for HybridPower and HybridSLI technologies as well as HDMI, 1066MHz FSB, both DDR2 and DDR3 memory support and more.
This is all just speculation for now but we may find out for sure by the end of September, which is when Apple will purportedly unveil its latest round of MacBooks.