Intel confirmed today that its Pentium 4 E (Prescott) processors will get 64-bit extension technology enabled in mid-year for 1P workstations, but remained tight-lipped on its mobile 64-bit CPUs.Source: X-bit Labs
“We have not gotten to that level of detail on PC clients so far,” an Intel’s spokesperson said.
In addition to actual 64-bit processors Intel will need to build supporting infrastructure for such chips, e.g., chipsets.
As reported earlier, the company’s Prescott micro-architecture already sports 64-bit capabilities. Remembering that there are Intel Pentium 4 E processors slated for launch later this year, we may anticipate that Intel will eventually enable the 64-bit support by the core as well as by the infrastructure. This would be the most cost-effective choice of adding 64-bit functionality to portable, but not really mobile computers.
Another processor lineup Intel has in its roadmap is Pentium M products tailored specifically for mobile needs and that does not have much in common with NetBurst architecture – the base for the Pentium 4 central processing units. Theoretically, Intel may incorporate its 64-bit enhancements into “non-NetBurst” processors too, but the question is whether there is any real need for 64-bits in thin and light notebooks.
Since high performance and additional computing functionality is generally expected from desktop replacement laptops, it is more logical to wait for Intel to announce a flavour of Mobile Pentium 4 E processor with 64-bit extension technology enabled.
AMD targets its Mobile Athlon 64 processors as well as DTR Athlon 64 processors for powerful notebook computers. For thin-and-light laptops it offers special versions of its 32-bit Athlon XP CPUs.
Intel to bring 64-bit extensions to notebooks, but not in short term

Intel said at the IDF that it is preparing mobile processors with 64-bit extensions. But these will not be available in the short term they said.