Mempile estimates that its disc technology will retain data for 50 years, but prototypes aren't expected for a year and a half. Drives and discs wouldn't be available to consumers until a year after that.
Soaring hard drive capacities have made backup via optical media difficult at best, so the prospect of terabyte recordable media is certainly tantalizing. However, by the time Mempile gets its TeraDisc technology out the door, terabyte-capacity might not be as impressive as it is today. You can read more about Mempile's TeraDisc here.