Intel Corp.’s Senior Vice President and General Manager, Digital Enterprise Group, Pat Gelsinger previewed Intel’s upcoming processor technologies this week, including details of a six-core processor due out later this year.

Gelsinger also detailed Intel’s new Itanium processor, codenamed Tukwila, as well as Nehalem and Larrabee, a future processor slated to have eight cores.

I’ll interrupt the oohing and ahhing here to note that Sun Microsystems Inc. has had an eight-core processor, Niagara, since 2006 and came out with an updated version, Niagara 2, or UltraSPARC T2, in August of 2007 for commodity servers.

But back to Intel’s big news; Intel plans to release its first 6-core, 45nm processor, code named Dunnington, later this year. The processor will feature a single-die with six cores and will be socket-compatible with the Caneland platform. Intel’s first 45nm processor, announced in November 2007, was a quad-core.

Dunnington will support FlexMigration technology, which supports live virtual machine (VM) migration across both 65nm and 45nm high-k Intel Core microarchitecture-based servers, so users who invested in 65nm quad-core Xeon processors recently won’t lose their investment.

Tukwila, meanwhile, is Intel’s next Itanium processor. With four cores, 30MB total cache, Quickpath interconnects, a dual Integrated Memory Controller and Remote Access Service features, the silicon holds 2 billion transistors and is expected to hold more than double the performance potential than current Itanium processors.

As for Nehalem, future versions will have from two to eight cores, with Simultaneous Multi-threading, resulting in 4 to 16 thread capability. Nehalem also supports four times the memory bandwidth than Intel’s highest-performance Xeon processor-based systems of today, with up to 8 MB level-3 cache, 731 million transistors, and QuickPath interconnects up to 25.6GB per second, Intel reported.

Meanwhile, Sunnyvale, Calif.-based Advanced Micro Device’s (AMD) 65nm quad-core Opteron processor, code-named Barcelona, will finally begin shipping in April after coming to a major standstill. The company told the world to expect shipments in September 2007, but discovered an errata and put off mass shipments of the processor.

AMD announced its plans for 45nm processors, code-named Shanghai, earlier this month and expects those quad-core processors to begin shipping later this year.