Toshiba claims they will be able to increase harddrive density by 10 times over 5 years using Nanocontact Magnetic Resistance, or NC-MR NC-MR uses an enormous difference in magnetoresistance which is achieved when two magnetic materials are situated close together and connected by a contact point that narrows to around 1nm. A prototype thin-film NC-MR structure fabricated by the research group exhibited a magnetoresistance ratio of 140% a room temperature.
Fijitsu claims that they will increase hard drive density by 5 times over 2 years using a new vertical magnetic recording tech based on crystalline magnesium oxide.
Seagate is promising the start of a transition to 37.5 terabyte drives starting in 2010 using HAMR(heat-assisted magnetic recording)
Other sources indicate the transition to HAMR will not start until 2012
Hard drives need to improve rapidly to stay ahead of faster and more energy efficient flash memory from Samsung and others