TDK Corporation recently revealed a roadmap that says 2.5” 640GB and 3.5” 2.5TB HDD should be available by January 2010 TDk themselves are a major player in the manufacture of read/write heads for many HDD suppliers. They are currently producing high density read/write heads for 250 GB/platter (2.5-inch) and 500 GB/platter (3.5-inch). They have however…