DDR3 memory, including 4GB DDR3 modules, is in the pipeline, from Samsung, Micron, and Nanya Technology. They have DDR3 memory modules that have been validated by Intel for the Centrino 2 platform, due out sometime in June. These range from 512MB to 2GB modules, however Micron announced this week that they will beging production of 4GB DDR3 memory modules sometime in the next few months. Intel is currently testing the modules.
They will require 64-bit Operating Systems to use the maximum memory available (Mac OS X, Microsoft Windows 64-bit Vista, Windows XP 64-bit, or Linux).
According to InfoWorld:
Intel Centrino 2 processor technology combined with DDR3 will provide higher performance at lower power levels for notebooks “and will become a major driver for early volume production of DDR3 beginning in the second quarter of 2008,” Samsung said in a statement Wednesday.