Not that unusal. Many motherboard mfgs simply leave off features to create a cheaper mobo. Lots of time you will see items listed in the docs as OPTIONAL. They don't create a new mobo design, they simply leave things off.
The first iMac had the space on the mobo for a floppy drive port. If you solder in the headers you can hook up a floppy drive to it.
http://www.heise.de/ct/english/98/18/134/