Nehalem is the code name for Intel's next generation microprocessor architecture, successor to the 'Core' architecture.

Based on the 45 nanometre manufacturing process, Nehalem promises a choice of two, four or eight cores and includes Intel's new QuickPath Interconnect, replacing the legacy front-side bus.
Information about Nehalem's launch is leaking like a sieve.
First, the text-only version of a press invite to an Intel event in Sydney March 30 displays "Intel Xeon Processor 5500 Series" where the graphic would otherwise be in the HTML version.
Server vendor Dell also has an event planned the same week in which it is expected to launch its 11th generation of servers, Cisco announced this week it will launch Nehalem-based blade servers in June and Sun Microsystems dropped the N-bomb while announcing their $30 million deal with the bureau of meteorology today.
Intel is expected to announce some ten Nehalem-based Xeon processors in the 5500 series (code named Gainestown) with speeds of between 2Ghz and 3.2Ghz.
Past press reports predict the 5500 series chips will cost anywhere between US$188 and US$1,600 on a per-thousand basis.