The new generation of helium filled HDD from HGST take their longevity seriously, rating them at 2.5 million hours MTBF.  This generation also has 7 disks squeezed into the shell, with current capacities reaching 8TB and a shingled 10TB model currently being tested for release later this year.  The increased life and storage density are only part of the benefits that helium brings, 23% lower operating power and temperatures 4-5°C lower than traditional drives will also have an impact on data centre operating costs.  In their article The Register did ask how long the HelioSeal will keep the helium contained and while they did not get an exact figure, the 5 year warranty gives you a good idea of a lower limit.

"HGST has announced second-generation helium drive tech after shipping a million gen-1 Helium drives and upping field reliability by 15 per cent."

Here is some more Tech News from around the web:

Tech Talk