Massimo Banzi announced it some minutes ago during his annual “The state of Arduino” presentation at Maker Faire Bay Area: Arduino Yún is the first of a revolutionary family of wifi products combining Arduino with Linux.
Yún means “cloud” in chinese language, as the purpose of this board to make it simple to connect to complex web services directly from Arduino.
Designed in collaboration with Dog Hunter, a company with extensive experience with Linux, the board adopts the Linino distribution which provides signed packages to ensure the authenticity of the software installed on the device.
Historically, interfacing Arduino with complex web services has been quite a challenge due to the limited memory available and they tend to use verbose text based formats like XML that require quite a lot or ram to parse. On the Arduino Yún we have created the Bridge library which delegates all network connections and processing of HTTP transactions to the Linux machine.
Arduino Yún is the combination of a classic Arduino Leonardo (based on the Atmega32U4 processor) with a Wifi system-on-a-chip running Linino (a MIPS GNU/Linux based on OpenWRT). It’s based on the ATMega32u4 microcontroller and on the Atheros AR9331, a system on a chip running Linino, a customized version of OpenWRT, the most used Linux distribution for embedded devices.
Like a Leonardo, it has 14 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator and a micro USB connector.
More info here.