It does require the help of a scanning tunneling microscope (STM) – a device in use in experimental physics labs for several decades but whose presence is still one of the best ways to identify a lab with a lot of grant money for research and one that hopes to get by with good math skills and plenty of pencils and paper.
It's hard to imagine a manufacturing process in which workers use electron microscopes to line up individual atoms to build components as they roll down the production line, not to mention a hard drive that needs one to read a piece of stored email.
But until you heard about nanopatterning data bits in clumps on a salted hard drive, using a laser to heat the hard drive just as a magnet imprinted a bit of data on it sounded pretty high-tech too, didn't it?
Given the length of time involved (years), I wouldn't bet too heavily that HAMR is going to be the single technology that's going to shatter the one-trillion-bits-per-inch barrier on hard drives you can pick up in Best Buy, or even in high-end servers and storage area network hardware.
When a technology is just on the edge of becoming the next big thing for long enough, something cheaper, faster and better usually cuts into line and steals all the accolades.
HAMR has all the hallmarks of one of the second-place finishers in that particular race; it was invented in the fifties, has been on the cusp of commercial practicality for a decade, just broke a major milestone of its own, but faces at least two more-advanced competitors, at least one of which is likely to be practical within the same window of time Seagate is planning for the advent of the HAMR era.
Storage isn't usually that exciting a topic, but breaking the terabit-per-inch barrier is a legitimate breakthrough.
I just doubt it's going to make much difference to either Seagate or hard-drive buyers anytime at all, not just any time this decade, as Segate hoped.