Intel has its tick-tock strategy, where every second year it has a brand new CPU, and a year after it has a die shrink or evolutionary successor to the original design.

Nehalem is a tock from a Penryn and it can be seen as a heavily boosted Penryn design with a lot of new features inside. Westmere is the next generation 32nm CPU, and according to IDF slides like the one from Mr. Stephen L. Smith, a Corporate Vice President Director of Group Operations Digital Enterprise Group, that you can find here (slide 24) there is a big indication that we should see first Westmere CPUs in 2009.

Nehalem's Chief Architect, Ronan Singhal, said that actually Intel didn’t announce the schedule for this CPU, which might even mean that this process and CPU might skip to 2010.