just divide the number by 400 and you get the 'edition' of it...
Firewire 400/400 = FireWire 1
Firewire 800/400 = FireWire 2
FireWire 1600/400 = FireWire 4... er... oh well
really, though, i don't think it's that hard to remember. (easier than remembering IEEE 1394a, -b, -c, etc.) And, while more ports is more confusing, having 2 different generations of firewire ports on the computer is no different than having firewire and USB ports (just because they're of the same kin doesn't make it any more confusing).
Also, USB 2's backwards compatibility has its problems. As far as i know, any USB 1 device on the bus will slow every device down to that speed. So, unless each USB port is on a separate bus (which may be more common than i thought, i don't know), it's not very practical.