Anyone remember the old days of USB 1.1? I do, every time I plug my thumb drive into an older computer and find myself waiting interminably for that 800 MB file to copy -- usually just before I have to catch a train.
USB 2.0's faster throughput hasn't become too uncomfortable yet, but as storage capacity increases and we start moving more data around (insert your own chicken-and-egg ruminations here), things should start getting uncomfortable pretty soon. Which is why Intel is working with other companies to establish the USB 3.0 spec, with theoretical speeds above 4 Gb (that's gigabits) per second -- nearly ten times the current 480 Mb/s rate. The hope is to get products out by early 2009, which should be around the time that USB 2.0's limitations actually start chafing.
The folks behind FireWire aren't sitting still, though; the 1394 Trade Association is currently working on a spec to bring the next generation of FireWire up to a speed of 3.2 Gb/s, and reviewing proposals for a 10 Gb/s spec as well. While it seems like a foregone conclusion that USB 3.0 will take the crown if they aim for a faster spec, other factors are also at play -- for instance, USB 3.0 might require shorter cables to maintain data integrity, while the FireWire group has already been actively exploring transmission over longer distances usign Cat-5 and Cat-6 cabling. In any case, it looks as if 2009 will be the year that you can fill up your 160 GB iPod without having to take a lunch break.