The ATA standard is evolving into Serial ATA, as 1394 is still better used outside the box. Serial ATA has some nice advantages for home systems, like standard placement of the connectors, meaning ease of having swappable drive bays. (More of a pro use then home, but right now it's not commonplace). Thus, you get a drive, add the rails your case uses to it, and slide it in the drive bay, similar to hot plug SCSI on servers (made easier with the SCA standard, same concept of standard placement on the connector).
A Legacy free system would be awesome. Some people think it would be difficult, but but look at the Mac users and how quickly they did it? Sure, some bought things like USB to serial converters and such, and also USB floppies, but when you have the entire markety shifting, it makes it easier.
The PC industry is getting there though. Many systems are finally shipping en mass with USB mice, keyboards and printers, 3 of the most common external devices people have when getting a new system.
And yes, Fibre channel drives are finally showing their face. They have been around for a while, but are just now starting to come into use in NAS and SAN enviornments. I haven't played with them yet since they aren't in my field of support yet, but I may look into them on some personal time since our lab has them.