serial is far from extinction. i wish i had more than two, i use them for multimedia buttons mounted in a break out box, and another for an ir remote control. the parrallel port controls an lcd screen for winamp time, and track display. its so much easyer to build things for serial and parralel ports, you dont need any processing chips to multiplex the commands into the single pair comunication of usb.
my computer is so fast, it completes an endless loop in less than 4 seconds!