"Thin" has some future-value if we're all going to be reduced to smart-phones with 12Tb drives and 2-inch screens. Yeah, I just can't wait to watch our video collection onto a THAT phone. Uh huh...
To me, "capacity" is more important than having a 2.5" drive thinned by a few milimeters. If they're still only 1Tb in capacity (as this article is ballyhoo'ing about), then I'll remain unimpressed and unwilling to spend a dime. In fact, I doubt I'd raise an eyebrow (or open a pocketbook) for even 2Tb, or 3Tb drives.
Practically speaking, of course, they want to get these skinny 1Tb drives out into the market for field-tests. Nothing else proves technology like actual usage (too bad, eh, Marketing Dept?).
It seems like, 10-15 years ago, I remember seeing articles about 1.6" drives and even .8" drives - with platters the size of a US quarter - as becoming the Next Big Development. Obviously, NAND & SSDs have or will supplant that development because, while the 1.6" drives were born, I don't think they're doing much kicking and screaming.
I don't believe Physical Size is going to influence the market - I think "capacity" still wins out.
At least until they hook all of us together and enforce subscriber demands that disallow storage at all. Then - when that happens - why bother with any capacity?