SourceSamsung claims to have engineered the first HDD disks that can store 1 TB of data on just one 3.5-inch platter.
Samsung has shown 2TB HD which only has 2 platters . This will allow Hard disks with space upto 3 and 4 TB. Currently maximum capacity for HD is 3 TB (750GB x 4)
Also company is showing 2.5" 1 TB (500GB x 2) HD for laptops. It isn't revealed when they will be released, though its expected to be sometime later this year.