Maybe Dell, Gateway, IBM/Lenovo, and Sony is different in Australia, but IEEE 1394 was on about 60% of their lineups on the first half of the 2000's. Most end users knew and still know what an IEEE 1394 port is. Even if they call it "that strange thing that connects to my microphone/hard drive/cable box/camera". It's well known to many in the US.
I've worked in and around IT for nearly 15 years now, a lot of that time with Windows PCs, plenty of Mac users know Firewire like the back of their hand, however in building PCs I've come to realise I've seen 1 maybe 2 firewire ports on most motherboards. Off the shelf/store bought PCs with propitiatory motherboards manufactured by specific brands, this may be a different case it's nothing I've really dealt with because it's the exception not the norm unless you're working where corporate support is needed that most of these grey box PC suppliers sell complete and utter junk that does the job just well enough to keep their tech support in a job, but not well enough not to frustrate the living daylights out of yourself.
The couple of industries where I've seen firewire come up often is in audio for desks and mixers, video conversion, capture and reccording devices and high speed data transfer where reliability is valued over flash in the pan "bursty" buses like USB.
That said, USB3 and Thunderbolt have gone and changed the game again.