I think that even with some USB peripheral devices you will still have to install the manufacturers device drivers, USB makes it possible to connect tons of devices to your computer without having to manually set IRQ's, DMA and such like in the old days.
  The main advantage of USB is the speed by which it tranfers data, it is much faster that the old parallel ports, especially the newer USB 2.0.

With USB, you can also have up to 127 devises pluged in at the same time.  Provided you have enough ports and hubs for them all.  As for the set up, things like mice, cameras, and most game controllersare simple enough to not need the instalation disc that comes with them.  But the more advanced things like your 4 in 1 combo can have a lot of different comands that are not as common as a mouse.  And right now, USB 2.0 is the down right fastest capable between USB and Firewire.  But Firewire will continuosly operate closer to it's max speed, which makes it ideal for video streaming.  Although there are some new things comming out in the near future that are supposed to be even faster.  i think one even reverts back to a serial type connecttion, or something strange like that.