Out of stock boards about arduino HOT 5 CLOSED

To my understanding, the emphasis is on the chipset driving the Arduino - the ATmega32u4 has built-in inherent USB support, which is why it must have been chosen for these demos.
You should be able to find plenty Arduino Micro clones out there on Ebay, though.

from arduino.

We're also looking into a new firmware for the ATmega16u2 found in boards using the ATmega328 as the application processor (such as the Arduino Uno R3). Right now the WebUSB library relies on the PluggableUSB capability supported by the 32u4-based boards. The ones without built-in USB support have an additional chip that provides USB-to-serial conversion.

from arduino.

It also appears that SparkFun has Arduino Leonardos in stock as well as 8 MHz and 16 MHz versions of the Pro Micro.

from arduino.

Great, I will try to acquire some

from arduino.

It seems that Arduino Yún is the logical replacement of the Leonardo, using the same processor:

https://www.arduino.cc/en/Guide/ArduinoYun

from arduino.