Actually, disk capacity, as expressed by the drive makers, has usually
used base-10 prefixes for quite some time. See
Certainly consumer-grade hard drives have had base-10 capacities for a
long time. I can't remember the last time I saw one that didn't. Go
to the store and look at any box with a hard drive inside.
When it comes to file sizes as reported by operating systems, well,
it's murkier. Modern Macs go with base-10 as well:
RAM is almost always expressed in binary terms, though.