Theo over at the Inq has it on good authority that while Nehalem will have the integrated memory controller, it will only really be enabled on the "Extreme" & server chips. The rest of the desktop & notebook chips will use the common northbridge (with memory controller)/southbridge configuration, which Intel will push into the 65nm process.

"This will finally mean that Extreme series of processors will start to justify the difference in price between regular desktop components and these premium parts, which are currently clocked as much as 3x more expensive than "regular" desktop part – with the only difference being 333 or 667 MHz difference in clock."