Why is the Leonardo listed as discontinued?

It's a very useful board, especially because it provides both a serial port and a USB port. This makes it possible to use it as an intelligent USB to serial link which is useful in all kinds of projects. If it's truly gone I will feel very sad.


How to define gone, hmmm….

Arduino.cc lost most of its manufacturing when one of the five founding members severed his relationship with the others and created Arduino.org. Arduino.cc has been reestablishing manufacturing via arrangements with Adafruit and Seeed, and therefore bringing boards like Uno and Mega2560 back to life. Meanwhile, Arduino.org continues to make their own Uno, Mega2560 and Leonardo boards like nothing ever happened. Leonardo is not discontinued over there.

Clone Leonardo boards continue to be available, probably from hundreds of manufacturers, so you're not going to find yourself unable to create projects with Leonardo. The official Arduino.cc Leonardo-like board is Arduino Micro. Spark Fun Pro Micro and DF Robot Beetle are derivatives. These are all Leonardos in miniature form, and continue to be available.