If you assume we're on 1 TB at the moment, and capacity doubles every 18 months (SSDs are a bit ahead of this at the moment), then 15 years is about right. By

If you assume we're on 1 TB at the moment, and capacity doubles every 18 months (SSDs are a bit ahead of this at the moment), then 15 years is about right. By 2030 seems like a fairly safe bet (barring major disaster before then). [Edit: Yes, thanks, I meant TB, not GB. Fixed.]