Intel's Nehalem with eight cores and sixteen threads will launch at some point in 2009. It will be an insanely big chip, as it will be a native eight-core with sixteen threads.
We were told that the new chip will have less L2 cache compared to the current Core 2 45nm Penryn generation, at least per core. You can roughly expect that the eight-core version will be a server part at first and then it might migrate to an ultra high end desktop extreme part.
We originally believed that the 8-core native Nehalem would have to wait for the 32nm development process that is scheduled for late 2009 to 2010.